
Class 
Book 



:Sa^ 



i 'U 



Gop^htN^ 



COPYRIGHT DEPOSIT. 



American 

Pattern Shop 

Practice 




By 



H. J. McCaslin 



First Edition 
1907 

Cleveland, Ohio 






LIBRARY of CONGRESS 
Two Cooles RecelTed 
MAY 6 190^ 

CLASS A XXc 

/'l 2^ 

COPY B 



'1' 
C, No. 



COPYRIGHTED 
BY 

THE FRONTIER COMPANY 
1907 



THH CLEVBLAND PRINTING COMPANY 
CI EVELAND. OHIO 



n^i ^DQ^ 



PUBLISHERS' NOTE 

The sections of this volume have been arranged as separate parts, 
each paged separately, the object in this being to enable the publishers 
to make revisions in future editions without having to destroy a large 
number of plates, as it is the belief of The Frontier Company that 
any book should be kept up to date by frequent revision. 

In order to make the index applicable to a book of this style, it 
has been necessary to combine with the page numbers a series of 
Roman numerals indicating the sections ; for instance, if one desires 
to look in the index for the Involute Odontograph Table, they will find 
a reference to 7-IV. This means that you must run through the book 
until the IV is found in conjunction with the page numbers, or in other 
words, turn to section IV and then to the 7th page. 

Both the author and the publishers will be very glad indeed to 
have anyone point out any errors or omissions in this work, or to 
suggest any additions or corrections which would improve future 
editions. 

The Frontier Company. 



PREFACE 

The literature pertaining to patternmaking not being as extensive 
as the importance of the business warrants, it has occurred to the 
writer that it would be well to offer some of the results of his own 
experience in the form of short articles and suggestions. 

Considerable writing has been done along this line and a number 
of books published, but nevertheless the writer believes that the field is 
large enough for one more which treats the subject in a somewhat 
different manner, as the molding and core making as well as the pat- 
ternmaking has been treated in each case. 

Patterns, rigs and methods for producing steel castings form a 
special feature, and the examples given are thoroughly explained as 
is also the subject of core molding and multiple molding for steel cast- 
ing work. 

Core box work is regarded as the most intricate and important 
part of patternmaking, and among the subjects selected as illustrations 
will be found excellent examples of this part of the work. 

While the art of patternmaking cannot be acquired alone through 
the study of books, a general and broader knowledge can be obtained, 
as no one individual can have the experience of manv. 

The variety of designs in castings and the conditions to be met 
make it impossible to apply any conventionary or set method to 
patternmaking at large, each particular object determining the method 
of molding and the construction of the pattern. In this connection 
it is desired that the succeeding articles be accepted as suggestions 
or examples, which have given practical results in the cases under con- 
sideration. Many, if not the greater portion of the subjects illus- 
trated and described in this volume have previously appeared as 
articles in the Anicricaii MachiiAst, Patternmaker, Wood Craft and 
the Foundry, under the writer's signature. In re-arranging the work 
under book form, many additions, alterations and corrections have been 
made in the original articles, and it is hoped that the volume will be 
useful to many patternmakers. 

The author wishes to acknowledge his indebtedness to many 
friends who have furnished valuable suggestions for the work. 



CONTENTS 

Section I 
ENGINE PATTEKNS 

PAGE 

A Slide Valve Cylinder l-I 

Pattern for a Low Pressure Cylinder 7-1 

A Piston Valve Cylinder Pattern 16-1 

Pattern for a Double Piston Valve Cylinder 30-1 

Patterns for a Heavy Engine Bed 39-1 



Section II 

MOLDING AND CORES 

Multiple Core Molding l-II 

Stacking Cores for Large Work 7-1 1 

Casting Round Flasks in Cores 11-11 

]\Iolding a Three-way Cock 14-11 

The Use of Covering Cores 17-11 

T Slot and Name Plate Cores 20-11 

IMolding in Cores 23-11 

The Use of Nail Cores 34-11 



Section III 
SWEEP WORK 



Sw^eeping a Plain Cylinder l-III 

Sweeping the Mold for a Suction Chamber 7-III 

Sweeping Cast Steel Slag Ladle Molds 12-III 

A Furnace Hopper and Bell 17-III 

Sweeping a Cylindrical and Conical Drum 24-ni 

Sweeping Rigs 36-in 



Section IV 
GEARING 



Spur Gearing 1-IV 

Bevel and Worm Gear Patterns 18-1 V 



CONTENTS 

Section V 
REPRESENTATIVE PATTERNS 

PAGE 

Pattern for a Throttle Valve Body 1-V 

Pattern for a Pinion Housing 8-V 

Hawser Pipe Patterns 14-V 

A Nozzle Pattern 20-V 

Molding Cast Steel Truck Bolsters 23-V 

Rig for Producing Cylindrical Castings 3 1-V 

Skeleton Patterns 39-V 

Pattern for a Chilian Mill Mortar 47-V 

Making a Crooked Elbow 56-V 



Section VI 

HINTS, SUGGESTIONS AND RIGS 

Cutting the Score in a Chain Drum Pattern 1-VI 

A Core Box and Clamp Combined 6-\ I 

Some Lath Tools 7-VI 

Wooden Ball Turning 9-VI 

Shrinkage 10-VI 

The Box Square 12-VI 

A Core Box Plane 13-VI 

Wooden Calipers 14-VI 

Elbow Core Boxes 1 5- VI 

Screws and End Grain 16- VI 

Warping of Castings 18- VI 

Arcs of Circles 21-VI 

Chords of Angles 24-VI 

Right Angled Triangles 26-VI 

A Table of Polygons 27-VI 

General Suggestions 29-VI 

Striking an Ellipse 41-VI 

Sawing Lags 44-\T 



SECTION 1 

ENGINE PATTERNS 

CHAPTER I 
A SLIDE VALVE CYLINDER 

Slide valve cylinders are made in a great variety of ways. I have 
chosen and illustrated a well known type with one head and a guide 
barrel cast with the cylinders, the guide portion being what is known 
as a bored guide. A plan of the cylinder is shown in Fig. 1, the plan 
being taken in such a position as to show the interior of the steam 
chest. At the right and left of the central figure there are two end 
views. In Fig. 2 the longitudinal section as taken on the line A A, 
Fig. 1, is shown in the center and at the right and left cross sections 
as taken on the lines B B and C C. These views show the arrange- 
ment of the steam ports, exhaust chambers, oblong openings in the 
guide barrel, etc. 

In beginning operations in making the pattern for this it is first 
necessar}' to make a full sized layout of the work, together with the 
necessary cross sections. The mode of molding which decides the 
parting of the patterns must next be determined. In this case the 
pattern has been parted longitudinally through the cylinder and steam 
chest. Along the line A A, Fig. 1, this manner of molding places the 
slide valve seat in the vertical plane which facilitates the setting of 
the cores. 

The construction of cylinder patterns of this class depends largely 
upon the size of the cylinder being made. If the diameter is to be 
less than 12 inches the body of the cylinder may be glued up practi- 
cally solid, but if the diameter is greater than 12 inches it is usuallv 
best to stave the body up, as shown in Fig. 3. The body having been 
roughed to form with the depressions to receive the flanges M N, 
Fig. 4, it is removed from the lathe and the flanges fitted in place. 
These flanges are first built up of segments, the inside sawed out, fitted 
in place and secured. The work is then returned to the lathe and the 
flanges and body turned to its proper dimensions, as shown in Fig. 4. 



2-1 



ENGINE PATTERNS 



The body is next taken apart and one-half carefully placed upon 
the layout and temporarily secured there. The blocks and pieces 
forming the various core prints and other projections are then fitted 
in place, as shown by the two views and section of the completed pat- 
tern. Fig. 5. The layout of the work gives the proper location for 
the dififerent parts as they are assembled. 




A box or block forming a half of the body of the steam chest, O, 
is gotten out and fitted in place with a core print P attached. The 
flange Q with stud bosses and stuffing box R with its core prints 
attached are secured in place. The steam intake core print S with its 
facing is prepared and attached, as are also the drain cock bosses T T. 



A SLIDE VALVE CYLINDER 



3-1 



The core prints U and V, for forming the oblong openings in the 
guide, are made, fitted on and secured. It will be noticed that the 
core print U extends each way beyond the openings and forms the 
core print W for the feet. 

The half pattern is next taken from the layout and turned over. 




the other half of the body placed on it and the fitting of the parts for 
this half proceeded with, the finished half serving as a guide. When 
completed the pattern is fitted with leather fillets and finished. 

Two views and a section of the steam chest core boxes are shown 
in Fig. 6. This illustrates the general construction and arrangement 



4r-I 



ENGINE PATTERNS 



of the parts. The loose pieces J in each end of the box form the 
stuffing and steam intake portions of the core. When the core has been 
rammed up in the box these loose pieces are withdrawn and the space 
occupied by them filled in with sand, so as to support the projecting 
parts of the core when the box is rolled over and also during the 
drying of the core. 

For receiving the ends of the steam ports and exhaust chamber 




G 



I —-Tm 




Fig. o. Steam Chest Core Box. Figr- 7- Steam Port Core Box. Fig. 8. Exhaust Chamber Core 
Box. Fig. y. .Assembled Cores 

cores one large print K is made of such a size that it will receive the 
ends of all three cores. This is better practice than the old method 
of using three separate prints, as it simplifies the setting of the cores 
and insures accurate measurement without greatly increasing the work 
of making the port cores. It is necessary to provide a projecting lip 
on the steam port cores to close the intervening space at L, Figs. 7 
and 9. This lip also gives a greater bearing surface to the core. 



A SLIDE VALVE CYLINDER 



5-1 



A section and end view of the steam port core box are shown in 
Fig. 7. It will be observed that a lip M M is allowed around the port 
and exhaust core openings, as shown in Figs. 7 and 9. This provides 
metal in the ports, so that the ports may be chipped to the correct 
dimensions, so as to give exactly the desired area and perfect cut-off. 

A core box for half of the exhaust chamber core is shown in 
Fig. 8. It is necessary to make two of these, one right hand, the 
other left hand. The core can be entire, or in halves and then fastened 
together. If it is made in halves it can be dried on a flat plate, which 
has some advantages. 

A longitudinal section of the assembled steam chest, steam port 
and exhaust chamber cores is shown in Fig. 9. This illustrates the 
manner in which the cores are secured together. The openings N N 




SECTION I 



Fig. 10. Core Box for Bore of Cylinder and Guide Barrel 



are provided in the bore core to allow the steam port cores to pass 
down into the bore core, thus holding them in position in the mold. 
These openings are made by the blocks N N in the core box, shown 
in Fig. 10. 

A plan and cross section of the core box for the core lor the bore 
of the cylinder and also for the guide barrel are shown in Fig. 10. 
The body of this box is staved up in the usual manner and planed out 
to size. The material for forming the oblong openings O O is gotten 
out and fitted to the sides of the box and secured in place. The sides 
of the box are then cut out to conform to the pieces attached. The 
beading P P is fitted around the opening and worked into proper 
shape, being secured in place with loose dowels. The side of the box 
at Q O must be made with loose pieces. In making the core the first 
section of the loose beading P P on the side of the box is drawn before 



6-1 ENGINE PATTERNS 

the box is rolled over. This allows the loose pieces Q Q to be drav n 
back. 

The manner of assembling the cores being shown in Fig. 9, it 
is unnecessary to show an illustration of the entire mold, as any molder 
would have no trouble or difficulty in coring up a mold made from 
the pattern. In Fig. 9 the manner of taking off the vent from the 
port cores is also indicated. 



LOW PRESSURE CYLINDER PATTERN 
y CHAPTER II 

PATTERN FOR A LOW PRESSURE CYLINDER 



7-1 



Several views of a low pressure cylinder for a marine engine 
fitted with a slide valve are shown in Figs. 11, 12 and 13. Fig. 11 
shows a half section and half plan. Fig. 12 shows a section on the 



FiK- n. Half Plan and Half Section of Low Pressure 
Cylinder 

Fig. 12. N'ertical Section of Low Pressure Cylinder 

Fig. 1.^. Projection of Steam Chest Side of Low Pres- 
sure Cylinder 




line A B C of Fig. 11, while Fig. 13 shows an elevation of the steam 
chest face of the cylinder. This type of cylinder is quite commonly 
used in compound marine engines. 



8-1 



ENGINE PATTERNS 



There are two ways in which the cyhnder may be molded, that is, 
the feet may be up or they may be down. A difference of opinion 
exists among foundrymen as to which is the more practical. Some 
claim that better results can be obtained by molding with the feet 
down on account of the fact that a large riser can be swept up around 



, Nb31iVd iHVd 




Fig. 14. Plan of Pattern Ready for Molding 
Fig. 15. Steam Chest Face of Pattern 



Fig. 16. Side of Pattern with Spindle and Sweep 
in Place 



the top of the cylinder to receive any impurities in the metal, and that 
this will insure a better and sounder barrel for the cylinder. On the 
other hand, the objection is raised to this method, that it is very diffi- 
cult to secure or hold down the barrel core on account of the fact that 



LOJV PRESSURE CYLINDER PATTERN 



9-1 



if the feet are clown the core must rest upon chaplets and has a con- 
siderable tendency to rise, thus necessitating special rigging" for bolting 
it down. 




Figr. 17. Steam Chest Core Box 




Fig. 18, Core Box for Exhaust Chamber Core 




Fig. 19. Box for making Port Cores 




Fig. 20. Core Box for Foot Fig. 21. Core Box for Exhaust Opening 

As most foundries make these cylinders in loam with their feet 
up when large enough to be swept, that method will be described first. 

Molding with the Feet Up 

In beginning this work it is customary to lay out a full sized plan 
and a vertical section through the barrel and steam chest, the allow- 



lO-I 



ENGINE PATTERNS 



ance for contraction varying from 1-16 inch to 1-12 inch per foot, 
depending upon the size of the cyUnder. The details of the pattern 
and sweeps are shown in Figs. 14, 15 and 16. l'\g. 14 shows a plan 
of the pattern in place. Fig. 15 a view of the steam chest face of the 
pattern, and Fig. 16 a view of the side of the pattern with the spindle 
and sweep in place. The view shown in Fig. 16 is a section taken on 
the line A B C, Fig. 14. 

The conical head with its flange is built up in segments and turned 
to the proper form. The upper portion of the steam chest is then 
built on to the side of the conical head, as shown in Fig. 16. The 
up])er portion of the steam chest, together with the conical head, is 
separate from the lower portion of the steam chest with a parting as 
shown. 




Fig. 22. Rig for Sweepinsr Barrel Core 



The stuffing box is turned up with a loose flange which is cut 
into sections and held with loose pins so that these sections can be 
drawn in. The ribs are usually attached to the stuffing box, forming 
a loose spider which is doweled in place upon the pattern for the 
conical head. 

The patterns for the feet are made in two sections and doweled 
together, the parting being in line with the top face of the cylinder 
flange. The central portion of the foot is drawn first and the pro- 
jecting portions or flanges drawn in. The portion of the foot pattern 



LOW PRESSURE CYLINDER PATTERN 



ll-I 



which forms the rib or connection with the barrel of the cyhnder is 
secured to the pattern for the head by means of pins and screws and, 
after the sweeping of the barrel has been completed, these are removed 
and this portion of the foot pattern drawn into the barrel. 

The face of the steam chest pattern is built to conform to the 
diameter of the barrel, 3-16 to ^-inch clearance being allowed for the 
sweep to pass. 




The interior of this pattern is so constructed and secured together 
with pins and screws that the middle section of each end can be 
removed from the inside, after which the pattern collapses, and allows 
all parts to be drawn in and removed separately. 



12-1 



ENGINE PATTERNS 



The core print for the steam chest is made as an open frame and 
secured to the chest with cleats, as shown in Fig. 16, braces beino- 
used across the face of the core print to keep it square. 




The core box used for making one-half of the steam chest core A, 
Fig. 23, is shown in Fig. 17. The prints for securing the steam and 
exhaust cores B and C are shown in place. 

The core box for making one-half of the exhaust chamber core 
is shown in Fig. 18. The top of this core being struck off. 

The port core box in which the two port cores are made, is shown 



LOW PRESSURE CYLINDER PATTERN 



13-1 



in Fig. 19. The top of this core is also struck off. The core boxes 
for the foot and for the exhaust connection are shown in Figs. 20 
and 21. 

The rig for sweeping the barrel core is shown in Fig. 22. A 
cast iron base plate A is first placed in position, a few courses of 
brick work built upon it and loam swept on to the outside of them 
by means of the sweep B, which during this operation is supported 




Fig. 35. First Operation in Sweeping Barrel Core 
Fig. 26. Second Operation in Sweeping Barrel Core 



by the upper sweep C and the temporary arm shown by dotted lines 
at E. The temporary arm E is then removed, the brick work built up 
and the plate F placed in position, after which loam is swept on by 
means of the sweep B which is carried by the sweep C and guided at 
the bottom by the loam already swept into place. The building and 
sweeping is continued until the entire outer surface has been finished, 
when the sweep B can be removed and the upper portion of the work 
finished with the aid of the sweep C, the stuffing box core being swept 
up at the same time that the portion of the mold on top of the plate F 



14-1 ENGINE PATTERNS 

is swept lip. When the stuffing box core is too small to be swept up 
in this way, a separate core is made and the print swept out to 
receive it. 

The low pressure cylinder described above is a good example 
of casting in loam. This method of casting is one used for producing 
intricate castings of large dimensions, in which it is not likely that 
the pieces will have to be duplicated many times. Frequently a large 
amount of work is required in designing the rigs and sweeps for 
loam castings, but on the other hand, the ])atterns themselves are 
usually inexpensive, consisting as they do of sweeps and forms. 

A section of the com]:)leted mold is shown in Fig. 23, showing 
the manner in which the different cores and ])arts are assembled. In 
beginning the mold, the cast iron foundation plate G, which is pro- 
vided with suitable handling lugs, is first leveled up and a socket 
provided for the spindle. The pattern is then placed above the plate 
and blocked in position. The overhanging ])ortion which contains 
the cope surface of the head is supported with temporary braces placed 
outside of where the bricking up is to be done. The space below 
the steam chest is then filled in with brick and a thickness of loam 
placed against the pattern. A seat or print H is swept up to receive 
the barrel core and a built up parting made around the outer edge, 
upon which the cast iron lifting plate I is placed to carry the middle 
section of the mold. This section is also built up of brick and loam. 
The sweep shown in Fig. 16 forms the outer diameter of the barrel. 

The steam chest face of the mold is left open, the brick work 
butting against the core print on each side, and the opening being 
closed later when the cores are in position. 

The top or cope part is formed by placing an ordinary flask on 
top of the brick work and ramming up a dry sand cope, care being 
taken to provide the necessary bars and skeletons for lifting out the 
deep pockets. 

The cope is lifted off, the pattern drawn, and the sections of the 
mold and barrel core placed in the core oven and dried. 

A pit is prepared and the foundation plate, or lower part of the 
mold, lowered into it and leveled up properly. The middle section is 
next placed in position, the offset parting guiding it into the proper 
relationship to the base. The core for forming the opening on the 
lower side of the steam chest is next set, the cores B and C having 
been secured to the cores A before they are placed in position. The 
upper cores are then secured together and placed in position. The 
cores for forming the intake and exhaust connections on the steam 
chest are usually inserted from the outside through openings left in 



LOIV PRESSURE CYLINDER PATTERN 15-1 

the brick work. The barrel core is next carefully lowered into position 
and chaplets are then placed on top of the barrel core and the cope 
placed on. 

The space between the walls of the pit and the mold is filled 
up by ramming in sand and provision made for the necessary gates. 
The mold is then weighted down, after which it is ready for pouring. 

Molding with the Feet Down 

The manner in which the pattern is fitted up for molding when 
the feet are to be cast down is shown in Fig. 24. The barrel is formed 
by a sweep in both instances. A ring is built up and turned, containing 
the lower flange of the cylinder, to which the feet and the ribs support- 
ing the stuffing box are secured. The upper part of the sweep is so 
arranged as to form a riser around the top of the cylinder. 

When this method is employed, the sweeping of the barrel core 
is somewhat more intricate, and it is shown in Figs. 25 and 26. It 
is first necessary to place the Prickard plate A with its face up as 
shown in Fig. 25 and sweep on the necessary thickness of loam with 
the sweeps B and C. The plate A is then dried and turned over, after 
which the brick work is built up and the main body swept by means 
of the sweep D as shown in Fig. 26. 



1&-I 



ENGINE PATTERNS 



CHAPTER III 



A PISTON VALVE CYLINDER PATTERN 



Piston valve cylinders, as the name implies, are cylinders in which 
the steam is controlled by a piston or cylindrical valve, moving in a 
barrel or chamber parallel to the bore of the cylinder. The example 
chosen to illustrate this type is a pattern for a 32 x 36 cylinder of the 
above mentioned design. This cylinder is for use in connection with 
a heavy duty reversible engine. Fig. 27 shows a half plan of the 
cylinder and a half section through the axes of the cylinder and the 




Fig. 27. Half Plan and Half Section of Cylinder 

steam chest, showing the plan of one port, relief valve opening, etc. 
By examining the plan view it will be observed that the cylinder is 
symmetrical about the center line A-A. 

A half elevation of the cylinder as seen from the steam chest 
side is shown in Fig. 28 together with a half cross section on the line 
B-B of Fig. 27. This section shows the metal thickness, etc. A cross 
section of the cylinder and steam chest on the center line A-A of 
Fig. 27 is shown in Fig. 29. This section serves to show the exhaust 
chamber, relief valve connection and bolting down lugs. The end 
view of the cylinder is shown in I'ig. 30. 



PISTON VALVE CYLINDER PATTERNS 



17-r 



Before commencing the construction of any part of the pattern its 
position and method of molding must be determined. Having chosen 
a horizontal position for the pattern under discussion, it must be 
parted through the axes of the cylinder and steam chest on the lines 
C-C, Figs. 29 and 30. 

Pattern Construction 

In beginning the work a full size lay-out or a partial lay-out is 
essential. As the cylinder and steam chest are symmetrical about the 
center line A-A, Fig. 27, it is only necessary to draw a one-half lay-out 



c- 




Fig. 28. Half Elevation and Half Section of Cylinder 



of the plan, with the outline of the steam ports, etc.. also a cross 
section as shown in Fig. 29, these two lay-outs being sufficient. 

The assembled and completed pattern is illustrated in plan iu 
Fig. 31 and elevation in Fig. 2)2, being shown in a reverse position 
to that in wiiich it is molded, this being the position the pattern 
occupied during assembling. 



18-1 



ENGINE PATTERNS 



For convenience in referring to the separate parts of the pattern 
during its description let us designate them as A, B C, D, etc., as 
shown in the completed pattern Figs. 31 and 2>2. 

Part A of the pattern is shown in plan and cross section in Fig. 33 
and consists of the lower part of the base of the cylinder. This can 
be constructed somew^hat after the manner shown. It will be observed 
by examining Figs. 28 and 29 that one-half of the cylinder and steam 
chest is contained in this part of the casting, being of course formed 
by the core. 

In commencing part A, three frames are gotten out, being nailed 
and glued together in a manner similar to that employed in the con- 
struction of segment work, that is, each frame is composed of three 




Fig. 29. Section on the Line .\ A, Fig. 27 



Fig 30. End View of Cylinder 



thicknesses of material. The two frames which form the ends of the 
base are covered or closed in with the proper thickness of material. 
After this is done one frame is laid out and sawed to the proper form 
of the base, less the thickness or lagging with which they are inclosed. 
This frame is then used as a templet to mark ofif the other two which 
are sawed to correspond. The three frames are then placed upon a 
level surface, lined and squared up and secured together in a good 
substantial manner with bars or braces. The lagging of the sides of 
the frames is then proceeded with. 

If the frames are laid ofif and sawed out accurately the lagging 
can be gotten out to the exact thickness and in narrow^ strips. It is 
then nailed and glued in place, when it will require but a small amount 
of dressing with a round sole plane, followed by the usual application 
of sandpaper. 

Next the. center lines of the cylinder and steam chest and of the 
bolting down lugs are carefully and accurately laid ofif across the 
parting of the pattern and down the ends and sides. 



^- 




Fi(J. 32 



Fig. 31. Plan of Finished Pattern 
Fig. 32. End Elevation of Finished Pattern 



*20-I 



EXGIXE PATTERNS 



Material is gotten out for the bolting down lugs and they are 
worked out and sawed to conform to the sides of the base, when they 
are fitted and secured in place. The two relief valve bosses, with 
their core prints, are also gotten out and secured in place. 

It will be found convenient in molding if these latter mentioned 
parts are attached with screws and loose dowels inserted from the 
interior of the pattern, as this manner of securing these loose pieces 
permits of their withdrawal from the sand during the finishing of 
the mold. 



ff— 




Fig. 33. Base Portion of Pattern 



It will be observed by examining Fig. 29 that the combined 
diameters of the cylinders and steam chest do not inclose the entire 
parting or top of the base, so that there is a space left between these 
two parts. For this reason the material A-Z is inserted and secured 
between the frames as shown in Fig. 33. 



PISTON VALVE CYLINDER PATTERNS 



21-1 



The pattern is next turned over and the bottom inclosed. It 
will be observed, however, that a portion of the material used in 
closing in the bottom is cleated together, this being done to allow of 
its removal to give access to the interior of the pattern for the removal 




A-T 



J'art B 



:A-r 



Fig. 35. Half Steam Chest Pattern 



Fig. 34. Half Cylinder Pattern 



of screws, loose dowels, etc., during molding. This loose bottom also 
facilitates the drawing of the pattern, as it affords the molder a good 
opportunity for rapping the inside of the pattern. 

The bottom having been dressed off and sandpapered, the core 
outline should be carefully laid out and dotted or painted in. This 



22 I 



ENGIXE PATTERNS 



is often considered unnecessary by patternmakers, but the writer be- 
lieves the time spent in doing this is invested to good advantage, as 
it shows the molder the metal cHstribution, which often determines 
the point of gating. Another good reason for drawing in a core outHne 
when no cope core print is used, as in the case under discussion, is 
tliat the molder can see at a glance where he must make provision 
for taking off the vent from cores which must be vented up through 
the cope. 




Fiff. 37 

Figr. 36. Half Flanges and Prints Fig. 37. Half Prints and Facings 



With the locating and placing of the conical core prints for the 
bolting down lugs, this part of the pattern is practically completed. 

Next one-half of the c\linder B and of the steam chest C, as 
shown in Figs. 34 and 35, are barreled or lagged up over built up 
frames as shown. These frames are built up and sawed out to the 
required outside diameter less the thickness of the lagging. As previ- 
ously stated, if the lagging is applied in narrow widths, very little 
dressing will be required to bring it to form. 

After the cylindrical part B has been worked up in this manner 
and dressed off, the material A-Y is applied to the ends to reinforce 
the counterbore at each end of the cvlinder. This material is dressed 



PISTOX VALVE CYLINDER PATTERNS 



23-1 



up and attached as shown. The stock can be gotten out in any con- 
venient width and owing to its being rather thin it will conform to 
the curve of the cylinder without any difficulty. 

In length these two half barrels or half cylinders B and C are 
equivalent to the length of the line A-X in Fig. 31, or the distance 
between the end flanges D of the cylinder and steam chest. 




Fig. 38. Steam Port Pattern 

Fig. 41. Stiffeninsr Rib for Steam Chest 



Fig. 39. Exhaust Cylinder Pattern 
Fig. 40. Stiffening Rib for Cylinder 



After completing these two parts and locating them on the base 
portion A, we proceed with the part D, as shown in two views, Fig. 36. 
This portion of the pattern forms the two half flanges on the cylinder 
and steam chest and also serves to secure the two half cylinders B 
and C together at their ends, as shown in Fig. 32. It will readily be 



24-1 



£.VG/.Y£ PATTERS S 



seen that two of these flanges will be required, one right hand and 
the other left hand, together with their respective core prints. These 
core prints are built up, turned and attached to the flange D, as shown 
in Fig. 36. 




Fig. 42. Plan of Core Box for the Steam Chest 



The parts E and F are shown in Fig. Z7 and simply consist of 
the half facings and core prints which are attached to the base of 
the pattern A for completing the flanges and core prints. Two of 
each of these will be required, one for each end of the cylinder and 
one for each end of the steam chest. 



PISTOX VALVE CYLINDER PATTERNS 



25-1 



After having secured parts B and C in their correct position upon 
the base A and fastened them together with the flanges D, our atten- 
tion is next turned to the getting out of the steam ports. One of these 
steam ports is shown in Fig. 38, and it is designated as part G of the 
assembled pattern, Fig. 31. Two of these parts are required, one 
right and the other left hand. Each one of these patterns is constructed 
in three pieces as shown. 




Fia. 43 



Section A-V 




Fig. 44 



Section A- V 



Fig. 43. Section of Core Box Fitted for Top Half of Core 
Fig. 44. Section of Core Box Fitted for B6ttom Half of Core 

On account of the irregular form of these steam ports, the largest 
portion of which extends from the center steam chest over to the 
cylinder, it will be found convenient to glue up a solid block and then 
saw it to form, rather than to attempt any form of built up construc- 
tion to save material. 

Having glued up two rectangular blocks of the required dimen- 
sions they are laid out and sawed to conform to the diameters of the 
cylinder and steam chest and fitted down into their correct position. 



26-1 



ENGISE PATTERS S 



Next, the two separate parts shown at the left of the figure are 
built up of segments fitted around and secured to the steam chest with 
loose dowels. After the above parts have been gotten out in this 
manner their outline is carefully laid off, the parts removed and sawed 
and dressed to size, when they are returned to their position. 

The exhaust chamber or part H of the pattern is shown in Fig. 39. 
This is built and turned up and then sawed so as to fit down in place 
as shown in Figs. 31 and 39. 




Fig. 45. Core Box for One-Half of Base 

With the getting out of the two stiffening ribs as shown in Figs. 
40 and 41 the pattern is practically completed. 

Core Box Construction 

The core box for the steam chest is illustrated in Figs. 42, 43 
and 44, it being so constructed that it forms one-half of the entire 
steam chest core, together with the port openings. The core being 
symmetrical about the center line A-W permits of its being reversed. 
This core box will form the two half cores required with the use of 
the change in outline of the bottom of the port openings, the provision 
for which will be described later. 



PISrOX I'AIJ-E CYLINDER PATTERXS 



27-1 



By examining the cross section of the cylinder as shown in Fig. 
29 it will be observed that the top and bottom outlines of the port do 
not correspond. This necessitates a slight change in the core box at 
these two points. In Figs. 43 and 44 are shown two cross sections of 
the core box on the line A-V, with its two sections showing the two 
different outlines of the port and the loose filling pieces required for 
altering their form. The upper section A-V shows the core box set 
up for the upper half of the core as shown in the completed mold, 
Fig. 49. The lower section A-\ is arranged for the lower core as 
shown in the mold, Fig. 49. 





rifj. 47 



Fiy. 48 



Section A-O 



Fig. 46. Core Box for Exhaust Chamber Fig. 47- Core Box for Holding^ Down Bolt Lugs 
Fig. 48. Core Box for OpeninH' for Relief ^'alve 

In constructing this core box the cross stringers are first gotten 
out, laid ofif and sawed to form to receive the lagging A-T. The 
stringers are next lined up and rigidly secured together by bottom 
and end cleats or by braces as shown. The lagging is applied and 
dressed out in the usual manner. The box is then completed by filling 
in the two spaces A-U with the required loose material somewhat 
after the manner illustrated. This loose material or series of loose 
pieces is intended to form the outline of the port openings. 

A plan and cross section of the core box used in forming one-half 
of the core for the base, which also forms the outside of the cylinder 
and steam chest, is shown in Fig. 45. It will be observed that by 
having two pieces, A-S, of opposite hands, that is, right and left, and 
also two pieces, A-R, right and left, together with right and left pieces 
A-Q and A-P, it is possible to set up our box for either one of the 
two cores required. The box or frame is constructed rectangular in 
form, the two sides being cut out to conform to the outer dimensions 



28-1 



ENGIXE PATTERXS 



of the cylinder and steam chest. To provide for the fiaring sides of 
the base the material A-N and A-M is placed in the two ends of the 
box as shown. The box is rammed up in the position shown and the 
top struck off with the straightedge to conform to the sides of the 
box. The parts are then withdrawn from about the core and the 
latter dried upon the plate upon which it was rammed up. 

The core box for forming the exhaust chamber core is shown 
in Fig. 46, tw'O half cores being made from this box. By examining 
Fig. 29 and the cross section ot the completed mold, Fig. 49, the man- 
ner in which this core cuts through into the steam chest will be seen. 
Some special provision is required at this point to take care of the 




Fig. 49. Cross Section of Mold 



irregular form of the core, and the material A-L is dressed up equiv- 
alent to the inner diameter of the steam chest at the point at which 
the exhaust core cuts through into the steam chest. This material is 
dropped through into the core box and secured with loose dowels 
as shown. Provision for the rounded corner A-K is made by cutting 
down into the box as shown. The depression not in use is stopped 
off or filled up before ramming the core. 

The half core box for forming one-half of the holding down bolt 
core is shown in Fig. 47, while one-half of the core box used for 
forming the relief valve opening is shown in Fig. 48. To assist in 
the setting of this latter core in its proper position the core print and 
core box are flattened off as shown at A-J. 



PISTOX J' AWE CYLINDER PATTERNS 29-1 

The bore or barrel core for the cyhnder is usually made in halves, 
with the aid of a core frame, or is struck up by the aid of heads secured 
to the core bar, the parts being subsequently bolted together through 
the core bar, as is shown in the center core, Fig. 49. 

Molding the Pattern 

A cross section of the completed mold on the line D-D-D-D, Fig. 
27, is shown in Fig. 49. This shows the method of parting the mold 
very plainly and also the method of setting the cores and the arrange- 
ment of the parts of the flask. The mold employed is what is known 
as a skin dried mold, that is, it is rammed up with green sand, the 
surface of the mold blackened as would be the case in a dry sand 
mold, and then the surface dried previous to pouring. 



30-1 ENGIXE PATTERNS 

CHAPTER IV 

PATTERN FOR A DOUBLE PISTON VALVE CYLINDER 

In Chapter II the author discussed the pattern work and two 
methods usually adopted in molding a low pressure slide valve cylinder 
of the marine type, together with the necessary sweeps required in 
forming the barrel of the cylinder and the bore or barrel core. In 
this article he will describe the general construction of the com- 
l)lete pattern for a double piston valve intermediate cylinder, with 
core boxes and the arrangement of the sweep for forming the bore 
or barrel core. 

Pattern Construction 

The position of this pattern during the operation of molding is 
with its feet up. Cylinders of this type are frequently used on quad- 
ruple expansion engines, and quite often reach such proportions that 
the sweeping of the barrel becomes an object, on account of the saving 
of material and floor space in pattern storing, and in such cases they are 
usually dealt with after the manner of the low pressure cylinder de- 
scribed in the former article. 

Three views of a cylinder of this design are shown in Figs. 50, 
51 and 52. Fig. 50 shows a half vertical section through the center of 
the cylinder and steam chest. Fig. 51 shows a half section and half 
plan of the cylinder, while Fig. 52 shows a half end elevation and half 
section through the valve openings. 

In beginning the work, it is essential to lay out a full sized plan 
and vertical section through the barrel and steam chest. The usual 
allowance for contraction is 1-12 inch per foot. Considerable board 
space can be saved if these views are laid out over each other and their 
outlines traced with difi^erent colored crayon or shellac so that they 
may be readily distinguished from one another. 

The manner of building up the first section of the pattern contain- 
ing the inclosed head of the cylinder, the stuffing box, feet, and a 
portion of the steam chest, is shown in Figs. 53 and 54. The web A 
is gotten out with a form coinciding with a section of the barrel and 
steam chest at this point. The ring B, containing the lower cylinder 
flange, is built up, turned, and placed uixm the web. The portion 
of the steam chest containing the lower steam chamber with the nozzle 
is now built on and up to the ring. The material used in closing the 
top of this ])ortion of the pattern being of the required thickness, is 
allowed to project outward so as to form the flange of the steam chest. 



DOUBLE PISTON VALVE CYLINDER PATTERN 



31-1 



The stuffing box is turned up with a loose flange, which is cut in sec- 
tions and held with loose pins, so that these sections can be drawn in. 
The ribs are usually attached to the stuffing box, forming a loose 
spider, which is doweled in place, allowing it to be lifted off with 
the web. 




Figr. 50. Half Vertical Section and Half 
Elevation of Cylinder 

Fig- 51 Half Section and Half Plan of 
Cylinder 

Fig. 52. Half End Elevation and Half 
Section Through Valve Openings 



^1 m i 



I '-^iiinSai'-J- S 




^ 



Fig. 50 



Fig. 52 



The patterns for the feet are made in two sections and doweled 
together, the parting being in line with the top face of the cylinder 
flange. The cope portion is provided with a loose flange which allows 
the central portion to be drawn first and the projecting portions of the 
flange to be picked in afterwards. The part of the feet extending 
down the barrel is secured to this portion of the pattern from the 
inside with loose pins and screws. A partial section of the barrel is 
shown in connection with the first section of the pattern in Fig. 55, the 
barrel being broken away in two places in order to shorten it up. 



32-1 



ENGINE PATTERNS 



It will be noted that there is a parting along the line C F F. The 
barrel of the cylinder is made up by building up rings, turning them 
and lagging these over. If the lagging is sawed quite narrow, it will 
require very little fitting and can be gotten out to the required thickness 
and then dressed off with a very small amount of work after it is in 
position. 




Fig. 53. Half Plan of Cylinder Pattern 
Fig. 54. Section of Top of Pattern 
Fig. .55. Partial Section of Barrel 



Fig. 55 



At the bottom of the pattern there is a flange which is parted from 
the lagged up portion as shown, the flange being built up, turned and 
doweled in place. In order to reinforce the portion of the cylinder 
opposite the counter bore at each end, it is necessary to introduce the 
lagging shown at H, at the top and bottom of the barrel. That at the 
top is secured to the barrel so that it will draw with it, but that at 
the bottom must be attached with loose dowels so that it may be picked 
in after the pattern is drawn. 

Two views of the steam port section of the steam chest are shown 
in Fig. 56, two of these parts being required. They are generally 
gotten out as shown, the sides being made up of segments and the top 
and bottom closed in. 



DOUBLE PISTON VALJ'E CYLINDER PATTERN 



33-1 



The exhaust chamber section of the steam chest is shown in plan 
and section in Fig. 57, the manner of construction being clearly 
shown. As will be noted the sides are lagged up over ribs built up of 
segments and cut out to the form of the outline of the pattern. 

The exhaust nozzle I, with its core print, is also shown attached 
by screws and loose pins from the inside. Three views of the upper 
steam chamber section of the steam chest are shown in Fig. 58, to- 
gether with the steam nozzle J, which is attached with loose dowels. 
This' part of the pattern is built up of segments and the side forming 
the top closed with material corresponding in thickness to the required 
thickness of the flange, the material being allowed to project over and 
form the flange as shown. On account of the fact that the steam 




Fig. 56 



Pig. 57 



Flange 



Fig. 68 



Fig. 56. Plan of Steam Port Section of Steam Chest Fig. 57. Exhaust Chamber Section of Steam Chest 
Fig. 58. Upper Steam Chamber Pattern 



ports are of a greater width and that they pass partially through the 
steam chamber, it is necessary to extend this portion of the pattern as 
shown at K. 

The assembled pattern is shown in Fig. 59, in the reverse position 
to that which it occupies in molding, but in the position which it 
occupied during the building. After the different parts are complete, 
the first section containing the inclosed cylinder head, etc., is blocked 
up upon the floor as shown. The barrel is placed in position upon it 
and secured with dowels. The various sections of the steam chest are 
then placed one upon another, each being located in its proper relation- 
ship to the others, by means of suitably placed dowels. 

The rib L, which connects the exhaust chamber with the barrel, 
and which is also shown in Figs. 50 and 51, is made with a joint 
lengthwise through its center, so that one-half of the rib can be 



34-1 



• EXGIXE PATTERNS 



drawn each way. that is. one-half into the barrel and the other half 
into the exhaust chamber. This is necessary on account of the open- 
ings in the rib, as shown in Fig. 50. 

Core Box Construction 

The core box used in forming the steam chamber, is shown in Fig. 
60, the sides being built up of segments, worked out to the proper 
form, doweled to the bottom board and parted as shown. This allows 
the bottom to be lifted off when the box is rolled over the sides to be 
drawn back, and the loose piece drawn out. 




Fig. 59. .Assembled Pattern 

The cores forming the steam chest must of necessity be placed 
one upon another when coring the mold, as shown in Fig. 63. and the 
vent taken off from one core to another and out through the cope. 
To facilitate the location of these cores in their proper relationship 
one to another, and to assist in carrying the vent from one core to 
another, a projection is made on the bottom of each core and a corre- 
sponding depression in the top of the one below to receive it, thus 
forming a male and female joint between the cores. The arrange- 
ment of the core box to form the projection is shown at R, Fig. 60, 
while the print forming the depression is shown in dotted lines at S, 
Fig. 61. These projections and depressions must be reversed from the 
bottom to the top of the boxes, as the case requires. 

The plan and section of the port core box, with the arrangement of 
sweeps for forming the outer surface of the circular portion of the 
core, are shown in Fig. 61. This box is constructed as shown, with 
the projecting arm or bracket, to which the sweep is secured with the 
center pin. In the course of ramming up the fiat portion of this box, 
a board with an opening to form the projection or print is secured to 



DOUBLE PISTON J'ALJ'E CYLINDER PATTERN 



35-1 



the box as shown by the dotted hnes at X. After the flat portion of 
the core has been completed, this board is removed, the sweep set 
in place, and sand rammed in against the circular portion of the box 
and struck off with the sweep. By referring to Fig. 63, it will be 
noticed that the two cores made in this box meet the barrel core in 
a different manner, that at the top having a projection which laps 




SECTION MN-O-P 

Figr. 60 



SECTION T-U-V-W 

Fig. 61 



Fig. 62 



SECTION AA-AA 



Fig- 60. Core Box for Steam Chamber. Fiff. 61. Port Core Box 
Fig. 62. Core Boxes for Exhaust Chamber, Feet and Exhaust Opening 



over the end of the bore, while the lower core abuts squarely against 
the barrel core. To provide for the making of the lower core, it is 
necessary to furnish a stop-off piece to stop off the core on the dotted 
line Z. 

A plan and cross section of the core box used in forming one-half 
of the exhaust chamber are shown at the left of Fig. 62. The drawing 
gives the general method of construction and shows the manner in 
which the rib is drawn out before the box is rolled over and taken apart. 

The foot core box is shown by three views in the upper right hand 
corner at Fig. 62. and it will be noticed that the top is struck off, the 
strike being shown below the core box. 

The core boxes for making the exhaust opening and the covering 
core used in connection with it are shown in the lower right hand 
corner of Fig. 62, and the construction and use will be evident from 
the drawing. 

Method of Molding 

The molding is carried on as follows. The foundation plate F, 
Figs. 63 and 64, is placed in position and leveled up. The pattern is 
then blocked up upon the same and the space below the pattern filled 



36-1 



ENGINE PATTERNS 



with brick, with a thickness of loam against the surface of the pattern. 
An off set parting is prepared parallel with the edge of the flange, and 
at a short distance from it, as shown at P. A lifting plate of proper 
form is provided and placed upon this parting as shown at K, and the 
brick and loam work continued up to the lower port chamber, as 
shown at G, Fig. 63. 

By referring to Fig. 50, it will be noticed that the form of the port 
chambers and the way they fit into the side of the barrel makes it 
necessary to form this portion of the mold upon cheek plates, as in- 




Fig. 63. Section of Completed Mold 



dicated by the dotted lines C, Fig. 51. An offset parting for this 
plate is made upon the surface G, Fig. 63. From the ends of this 
cheek plate it will be necessary to carry up a vertical parting clear 
to the top of the mold, this vertical parting extending on a radial line 
from the barrel of the cylinder. The brick work is then continued 
until the upper port chamber is reached, where it is necessary to make 
another parting,. as shown at H, and place another cheek plate, similar 
to that placed upon the parting G. T'iC brick work is then continued 
to the top of the mold at I, and a parcing prepared for the cope which 
is rammed up in dry sand in an ordinary iron flask. 



DOUBLE PISTON I -AWE CYLIXDER PATTERN 



37-1 



After the mold is completed, the cope is lifted off and the first 
section of the pattern containing the inclosed cylinder head is drawn. 
This gives access to the interior of the barrel and allows the pins and 
screws securing different parts of the pattern to the barrel to be re- 
moved. The barrel is then drawn. The cheeks are then lifted away, 
and the different sections of the steam chest pattern behind them 
drawn as they are exposed. The plate K, which supports the outer 
wall of the cylinder and the lower section of the steam chest and 
cylinder flange, is then lifted off and while suspended the lower por- 
tion of the pattern is drawn down from it. 




Fig. 64. Sweeping the Core for Cylinder 

The parts of the mold which have been removed are then placed 
in the oven to dry and the spindle is located in the center of the 
cylinder for sweeping the barrel core, as shown in Fig. 64. The barrel 
core is swept up with brick and loam in the usual manner. The lower 
arm B-B (shown by dotted lines) is removed when the brick work 
reaches this height, and the completed portion of the sweep surface 
is used as a guide for the lower end of the sweep. A cast iron plate 
is placed on top of the brick walls, close to the top, and the upper 
surface finished as shown, with the seat or print swept in the center 
to receive the stufBng box core. 

The stuffing box core is shown in detail to the left of the upper 
part of the spindle in Fig. 64. The barrel core supported by the 
plate is now placed in the oven and dried. 



38-1 EXGIXE FATTERXS | 

The assembling of the mold is as follows : The foundation plate 
1\ with the barrel core and the seat upon it, is lowered into the pit 
and leveled up. The plate K supporting the outer wall of the barrel 

is next placed upon it. The cores and cheeks forming the steam j 

chest are now lowered into place in their proper position. '• 

The nozzle cores are inserted from the outside of the brick work ' 

through openings left for the purpose, and the openings closed with ] 

the covering cores. i 

The gates and runners are prepared during the building of the 

mold, the cope placed in position, and the intervening space between \ 

the mold and the pit wall firmly packed up by ramming in sand. i 

The cope is then weighted or bolted down, when the mold will be ' 

complete and ready for pouring. I 



HEAVY BED PATTERNS 39-1 

CHAPTER V 

PATTERNS FOR A HEAVY ENGINE BED 

Engine frames or beds assume various forms, being chiefly de- 
signed to suit the work and requirements in each particular case. 
Shown in the accompanying illustration is a familiar form of a heavy 
duty, or what is sometimes termed the Allis type of bed. This form 
is especially adapted to heavy mill work, and the engines are frequently 
made and connected up in pairs, the dimensions assuming large pro- 
portions. 

The one under discussion is the right hand bed of a pair of 
reversible, piston valve blooming mill engines. The general practice 
with concerns building engines of this type is to construct the bed 
patterns so that they will serve for both right and left beds, and also 
for engines of different strokes. There are a number of different ways 
in which a pattern of this nature can be constructed, and it may be 
difficult to decide which is the most practicable and economical both 
for the patternmaker and the molder, for in all such work both the 
patternmaking and the molding should be taken into consideration. 

As the duplication of these bed castings is frequent with concerns 
doing this class of work, the construction of a complete pattern is 
usually considered the most economical. 

Construction of the Patterns 

The pattern can be constructed to serve for both the right and left 
bed somewhat after the manner illustrated and described in this 
article. Fig. 65 shows the plan and elevation of the bed showing its 
general outline and the metal distribution. It also shows the points 
at which the cross sections illustrated in Figs. 67, 68, 69, 71, 72 and 73 
were taken. These cross sections should receive close attention from 
the patternmaker, in order that he may obtain a thorough knowledge 
of the requirements in making up the core boxes. 

Viewing the frames from the front it would appear as illustrated 
in Fig. 66, while the cross section on the lines AA, BB and CC would 
appear as shown in Figs. 67, 68 and 69. Fig. 70 shows the outline 
of the back or cylinder end of the frame, while Figs. 71, 72 and 73 
illustrate the cross sections on the lines DD, EE, FF as they would 
appear from the cylinder end. 

Of course, the first thing would be for the patternmakers, foun- 
drymen and others interested, to get together and thresh out the 



40-1 



EXGIXE PATTERXS 




Fig. 65. Plan and Elevation of a Large Engine Bed 



HEAVY BED PATTERNS 



41-1 



general discussion of the molding, shrinkage, arrangement of cores 
and the construction of the pattern. When this has been done a full 
sized layout giving both the plan and elevation with core outline or 
metal distribution is essential. It is also necessary to draw a number 



a 




Fisr. 66. Front End View 



Fig. 67. Section A A 




Fig. 68. Section B B 



Fig. 69. Section C C 



of cross sections, say for instance, AA, DD, EE and FF. To econ- 
omize the layout board surface, these layouts can be made over one 
another and dotted in with different colored crayon or shellac, which 
will enable the workmen to distinguish one section from another with- 
out difficulty. The shrinkage usually allowed is 1-12 of an inch per 
foot, with a liberal allowance for finish upon all machined surfaces. 

It might be well to state that in the construction of large patterns 
the closer the exact dimensions are worked to, the easier will the work 



42-1 



ENGINE PATTERNS 



be comp eted. That is, allow scarcely any material for dressing to size. 
Place what draft is desired upon the frames, and inclose them with 
the required thickness of material. Then the only work necessary is 
the cleaning and sandpapering of the pattern. 




Fig. 71. Section F F 



Fig. 70. Back End View 




Fig. 73. Section D D 



Fig. 72. Section E E 



To facilitate the altering of the pattern for different strokes, as 
well as the handling and storing of the same, it is built in sections and 
assembled as illustrated in Fig. 74, which shows the general construc- 
tion, the joints of the various sections or parts, together with their 
attached core prints, loose pieces, etc. 



44-1 



ENGINE PATTERNS 



To aid us in referring to the different sections or parts during a 
discussion of their construction, let us designate them as sections 1, 2, 
3, etc. Sections 1, 2, 3 and 4 comprise the forward or bearing portion, 
while sections 5 and 6 comprise the cross head housing, and part 
7 the bracing member. 

As section 1 usually receives the initial attention, let us proceed 
with its construction as shown in Fig. 75. This section, together 
with sections 2, 4, 5 and 6, are used for both right and left hand 
beds. It will be observed that in using this section for both right and 
left hand patterns it is necessary to make right and left hand corner 
pieces G and H, and also to provide for the reversing of the strips 
forming outline of the crank-pit core print I, and the covering material 
J, Fig. 75. 




^Covering tt 



Fig. 75. Section 1 of Pattern 



The frames can be gotten out, secured together, and the sides 
inclosed somewhat after the manner illustrated. Offsets are formed 
on the line KK to receive the right and left hand corners G and H, 
which are next built in place and secured with dowel pins and screws. 
The covering material J is next added, and the strips forming the 
outline and thickness of the core print I attached. This manner of 
forming this core print answers the purpose very well, and permits of 
an opening through the pattern to facilitate the ramming of the 
mold. In closing the bottom N, the material can be cleated together 
in two or three sections, which permits of its easy removal giving 
occess to the interior for the withdrawal of the screws and pins, and 
for the rapping and drawing of the pattern. 



HEAVY BED PATTERNS 



45-1 



Fig. 76 shows a plan, elevation and end view of section 2 of the 
pattern. The frames O, as shown in the end view, are nailed and 
screwed together, and covered with stock to form the required outline. 
As this section is employed for both right and left hand patterns, it is 
necessary to make an offset on each side along the lines LLL. This 
space is then filled with a right and left hand piece shown above and 
to the right of the other views. The right hand piece being shown in 
place in Fig. 76. 

Next the core print M is attached, a section of which is shown 
in greater detail to the right of the plan. Attention is called to the 
strip P around the outer edge of this print. The strip being added 
to assure a perfect setting of the core, for any sand disturbed in the 
placing of the bearing core in position, will fall down below the seat of 
the core and into the depression left vacant by the strip P. 



Loose 




Fig. 76. Section 2 of Pattern 

The loose facings and the holding down bolt lugs, having been 
gotten out are attached with loose dowels, and this section is then 
ready to be placed in position upon section 1, the two parts being 
secured together M'ith dowels and screws. These dowels and screws 
must be so arranged that they are get-at-able when the bottom is 
removed from section 1. 

It is next necessary to construct that part of pattern designated 
as section 3, as shown in two views and a section on the line QO in 
Fig. 77. For this section it is necessary to build a complete right hand 
and a complete left hand piece. Owing to the irregular form this 
section is the most difficult to construct, and it is advisable to build 
it in its correct position upon section 1, with the end fitting against 



46-1 



ENGINE PATTERNS 



section 2, as shown in Fig. 74. First the lower part of the core print 
to the center line or height R, and with a width equal to S, is framed 
up and the top and end closed in. The projection which fills in the 
offset on the line LL of section 2, built up as shown at Y. The arch 
frames T and U are now gotten out and placed in their correct 
position. These frames differ in form, frame T being of an elliptical 
shape, while U is circular. As the required opening is given through 
the rib D, section 1, it will be found convenient to locate frame U 




Section O-O 

Figr. 77. Section 3 of Pattern 

at this point and lay it out accordingly. Of course, allowance must 
be made for the round corner CX, Fig. 65, which would make the 
core print that much larger in diameter. The lagging is now placed 
on and dressed to its proper form. Frame W is then set in position, 
and the width X built up to the point of tangency with radius ^. 
Lagging a is now fitted on, dressed to form and the fillet h worked 
out. 

Section 5 as shown in plan and cross section in Fig. 78 forms the 
cross head housing, and is used in both right and left hand patterns. 
The use of this piece for both right and left hand patterns necessitates 



HEAl'Y BED PATTERNS 



47-1 



the building of oblong openings in each side, the one not in use being 
closed or stopped off by the bracing member or section 7, Fig. 74. 
It will be observed that this part of the pattern is built the full height 
and secured to the end of sections 1 and 3 with pins and bolts. The 
frames are usually gotten out as shown in the cross section de. These 
frames are lagged over forming the depression c on the sides. This 
depression has a depth equal to the metal thickness which allows the 
core to cut through when placed in the mold. The oblong openings 
are now built in with that portion above the center, as shown at g 
secured wath pins, so that it may be drawn in after the pattern is 
removed from mold. 




Fig. 78. Section 5 of Pattern 



The cylinder end of section 6, is shown in two views in Fig. 79. 
This portion is used for both right and left hand patterns with prac- 
tically no change. The frames, two in number, are gotten out and 
secured together. It will be observed that the outer one, as shown 
in the end view, is partially closed, leaving a square opening to be cov- 
ered with the attached core print. 

These two frames are lagged over, provision being made to secure 
the loose pieces HI which are left detached from the pattern to facil- 
itate its drawing from the sand when checking off this portion of the 
pattern. These loose pieces are next fitted in place and secured, when 
this portion of the work receives its dressing up, corners rounded, etc. 



48-1 



EXGIXE PATTERXS 



The core print, one-half of whicli is shown in two views, Fig. 80, is 
staved up, the forms being gotten out and covered with lagging and 
turned in halves, the lower or drag half is secured in its proper position 
to section 6 with screws and loose dowels, and the upper half placed 
upon the lower half. Segments forming the loose facings JK are next 
attached when this section will be ready to secure to section 5, as 
shown in Fig. 74. 

Section 7 — or what is sometimes termed the bracing member, is 
shown in three views. Fig. 81. It is necessary to make both right and 
left hand patterns for this. The section is built in its proper position 
to the assembled sections, as shown in Fig. 74, the frames having been 



Iioose^y 




Fie, 79. Section 6 of Pattern 



Fig. 80. Core Print for Cylinder 
End of Pattern 



nailed up with ample stock allowed for fitting and sawing to size. 
They are fitted to the sections 2, 3 and 5 and secured in place with 
screws and pins. 

The proper outline of the section is next laid ofT upon them; 
they are then removed and sawed to size and returned to their proper 
position, where they are secured and well braced together. The 
material inclosing the top and side is next placed in position and 
dressed up, and the core print LM attached. 

The large fillet shown in two views in the lower right hand 
corner of Fig. 81 is gotten out, and fitted in place up to section 3 
and worked out to shape. 

With a dressing up and finishing of the assembled sections of 
the completed pattern, this part of our work is done, with the excep- 
tion of the crank pit extension, as shown in two views in Fig. 82. 
This is constructed by getting out sides and center rib, securing them 



HEAVY BED PATTERNS 



49-r 



together with separating pieces and then lagged up. To avoid the 
end grain of the material used in the lagging, shown on the sides of 
the pattern, the sides are gotten out of the required form, and the 
lagging fitted so as to butt against the inside of these pieces, that is, 
to fit between them. This necessitates a segment, which forms a 
shoulder to receive the lagging, and is placed in position and secured 
to the inside of the side pieces. The lagging afterwards is placed in 
position and dressed off to conform to the sides. This section is used 
for both right and left hand patterns. The one change necessary is 
the change of its position on section 1. 




Fig. 81. Section 7 ot the Bracing Member 

The holding down bolt lugs, etc., are now fitted to the assembled 
pattern. The various sections given designating marks, so that they 
can be returned into their proper relationship one to another, after 
which the pattern is dismantled and set up in a reverse position as 
required for the left hand pattern, the various left hand sections built 
in just as the right hand sections were. 

Construction of Core Boxes 

The core boxes, fifteen in number, next claim our attention. For 
convenience in referring to the various core boxes employed in form- 
ing the interior of the frames they are designated, Al, A2, A3, etc., 
the location of the cores being shown by the letters placed on Fig. 65. 



50-1 



ENGIXB PATTERXS 



As the most of these boxes are of simple construction, we will illustrate 
only those, with the exception of A3, receiving core print settings. 
The ones illustrated embrace the most intricate boxes in the set. All 
of the boxes are made of rectangular form, and are all employed for 
making both right and left hand cores. The form of the cores and 
changes from right hand to left hand being made by changing the 
position of the filling in pieces, or by the use of right and left hand 
sections of the boxes. 

We will first consider the construction of the boxes used in form- 
ing core Al. This core forms the upper half of the interior of the 
cross head housing, and is supported in the mold by its projecting 
core prints, as shown in Fig. 74. This box is, with one exception, the 




Fig. 82. Crank Pit Extension Pattern 

largest and most intricate box to construct. It is shown in plan and 
longitudinal section through the center, and a cross section on the 
line LM, in Fig. 83. 

Material of about 2>4 inches by 6 inches for forming the rect- 
angular frame is first gotten out and secured together in a good sub- 
stantial manner, about as shown. The cylindrical part forming the 
projecting print portion at the right of the figure can be staved up 
and dropped into place. The board forming the taper on the end of 
the print is fitted in separately. The segments forming the depression 
() are now nailed up, layed off, sawed out, dressed to the proper 
form, dropped into place and secured, and the staving up of the barrel 
proceeded with. 

The depression R is also built up of segments, dressed out and 
fitted in place. It will be observed that a slight change is required 
at the top of the box at this point, for the right and left beds, and 



HEAVY BED PATTERNS 



53-1 



that this necessitates the changing of the blocks S and T. The cross 
head guide U is now lagged in with the shoulder V arranged as 
shown to support its projecting end, or loose piece W. This loose 
piece W must be drawn back out of the core after the removal of 
the boxes. As the remaining portion of the box cannot be used for 




Fig. 85. Core Box A 3 



Hectioii Ji D 



both right and left hand patterns, it becomes necessary to construct 
a full right and a full left hand section for the portion marked X. 

The core print portion having been lagged up and dressed out 
to conform to the core print of the pattern, the outline of the round 
corner is next laid off or transferred to the surface. This can be 
done very nicely and accurately by placing heavy paper over the core 
print on the pattern and fitting it up against the rounding surface at 
the intersection of the core print and the pattern. The paper is then 



54-1 



ENGINE PATTERNS 



placed in the correct position in the core boxes, after which the fiUing 
in pieces or lagging, are fitted to its outline as shown by Z. 

Material is now added from which the pockets AB and AC, as 
shown in section LM, are worked out. The blocks or loose parts AD 
and AE are fitted above the pockets AB and AC. 

It will be noticed that these loose pieces AD and AE must be 
removed and the openings left vacant by them filled in with green 
sand to support the overhanging projections after the box has been 
turned over upon the core plate. 



Fig. 86. Core Box A 4 




Section It L 



Section £ JtT 



The board AF is now fitted into the end of the box to give the 
proper taper to the end of the core. The core print AG which is 
suspended from the top of the box is located and doweled in place. 
This core print AG forms the interior setting for the oblong core 
A15, which passes through the core A14 intended to form the interior 
of the bracing member. This core print is made longer than the 
setting of the cores requires owing to the fact that the core has to 
be placed in the depression left vacant by the core print, and then 
shoved forward through the core A14 and into the impression left 
by the core print on the pattern. The portion of the core print left 
\'acant after the core A15 has been shoved to its final position may 
be stopped off with sand. 

This completes the core box for the right hand bed. In making 
the changes for the left hand bed it is necessarv to build a left hand 



HEAVY BED PATTERNS 55-1 

section X, and to get out pieces S and T of the opposite hand. It is 
also necessary to change the beading P around the oblong openings 
in the side of the cross head housing to the opposite side of the box. 
The suspended core print AG is also changed from one side of the 
box to the other. 

Fig. 84 shows a plan, a longitudinal section through the center, 
and a cross section on the line AH of the core box used in forming 
the core A2. This core when placed in position upon core Al com- 
pletes the interior of the cross head housing, and also the exterior part 
of the bed leading down into the crank-pit. While this illustration 
is almost self-explanatory a few remarks may not be out of order. 
The frame is constructed about the same as for the box previously 
described, and the filling-in sections made, dropped into place and 
secured to the frame. It will be observed that the only two sections 
employed for both the right and left hand beds, are the center section 
or that part which contains a cross head guide, and the round core 
print HI. With the two parts HI, and the part for the cross head 
in place, the bottom board Y is fitted in, and the side pieces AJ and 
AK dropped into place upon it. The side pieces for the center section 
having been gotten out and secured in place, the change pieces AL 
and AM are fitted in, as well as board AR, which contains the circular 
opening at the forward end of the housing. With the suspension of 
the core print AG, which can be used in both boxes Al and A2, 
the getting out of the beading AS around the oblong opening on the 
side of the housing, which matches the beading of the core box shown 
in Fig. 83, this portion of our box is completed and the lagging in 
of the section AO proceeded with. Owing to its irregular form and 
the provision which has to be made for taking care of the rounding 
corner AT, it will be found convenient to make the section in four 
pieces and join them at AU and the sides along the line AV as shown. 

Core A3 which forms the metal thickness of that portion of the 
frame directly forward of the cross head housing is made in the core 
box shown in plan and two cross sections in Fig. 85. This is a 
large cumbersome box for making a comparatively light core which 
is due to the built up form BE, which occupies the greater part of 
the box interior and conforms to that part of the frame extending 
down into the crank-pit. Of course, in constructing this part of the 
box, allowance is to be made for the metal thickness. Practically 
none of this box can be used for the opposite hand bed except the 
frame, which is put together as shown. The form BE is lagged up 
ever supports, dropped into place and secured with pins. The material 
forming the outline of the sides BF and BG is gotten out and fitted 



56-1 



ENGIXE PATTERNS 



in position. Referring to the cross section CC as shown in Fig. 69, 
which gives the exact outline of the core required, it will be seen 
that the filling in pieces BH and ]]I are required to form the desired 
height and outline of the upright projections as shown in Fig. 85. 
This box is completed by placing in position the internal flanges Bf 
and the metal thickness around the holding down, bolt boss BK. 

The plan and two cross sections of the core boxes used for form- 
ing the core A4 for the crank-pit, are shown in Fig. 86. This box 




Fig. 87. Core Box A 5 



Section B-O 



consists of a frame the sides of which conform to the desired height 
and form of the core, the box being rammed up. struck off and the 
pieces BN and BO which support the part of the fillet extending into 
ths core bedded in. It will be observed that this fillet is the continu- 
ation of the fillet formed in the core box A2, and which runs out at 
this point in the crank-pit. 

To avoid the sharp corner around the side and end of the pit. 
an offset as shown at BP is arranged for. 



HEAVY BED PATTERNS 57-1 

Core A5 which forms the main bearing, is made in the core box 
shown in Fig. 87, the box being constructed somewhat after the 
manner iUustrated. After the frame is completed the material RS 
forming the T head facings is made and held in place with loose pins. 
To form the openings through the metal on each side of the bearing 
material, the thickness of which is equal to the metal thickness, is 
dressed up and fitted to the box, and the required openings cut out. 
The facings BT must also be secured to the openings. The circular 
pieces on top of the boxes are next attached, and to them are secured 
the two supports for carrying the circular facings BU. 

The seven core boxes or frames used in forming the remaining 
ten cores are not illustrated, as they are of a comparatively simple 
nature, so that a description of their general construction and manner 
of changing from right to left hand will be sufficient. There cores. 
with one exception, core A15, have no core print setting, being secured 
in the mold and in their proper relation one to another with chaplets. 

Core AlO forming the interior of the bed underneath the main 
bearing is made in halves, the two halves being joined together with 
the vertical plane on the center line of the longitudinal rib. As the 
core is sxmmetrical about the center of the rib, one-half of the box 
without any change is all that is required, the two half cores being 
simply turned over and pasted together. This box consists of a frame 
and a bottom board, upon which one-half of the thickness of the rib 
is attached. Xext material giving the circular form at the bottom of 
the bearing, and to form the internal flange at the bottom, together 
with the cross rib. is placed in the box. 

Directly in front and back of the main bearing and extending 
the entire height of the bed are cores A6 and A7. These cores are 
also made in halves, being parted in the same plane, that is. along 
the center rib as was the case in core AlO. These four half cores 
are made from the same frame and upon one bottom board. It will 
be observed that core A7 is of triangular form, while core A6 is 
rectangular. As the latter core is the largest the frame and bottom 
board are made to correspond with its size and filling in pieces used 
when making the triangular core A7. In ramming up core A7, the 
bottom of the box forms the joint of the two half cores, while the 
top of the box forms the joint in core A6. This necessitates the sus- 
pension of one-half of the thickness of the rib from the top while 
making core A6. the change being due to the fact that it is necessary 
to fill in the bottom board with material to obtain the outline of the 
metal on the sides, also the internal flange holding down both bosses, 
etc., which are attached to the side of the box. 



58-1 ENGINE PATTERNS 

That part of the bed between the crank-pit and the extreme front, 
and which extends part way down the side of the bed, is formed 
with tlie core A8. This core is made in a rectangular frame with 
bottom board, the frame being gotten out the required height and 
length, and with a width which will allow the placing in of a rec- 
tangular stopping off board conforming to the angle of the crank-pit 
end. It will be seen that this stopping off board does not extend the 
entire length of the box, but only that portion required in forming 
the metal thickness across the end, and upon a portion of the side 
of the crank-pit. 

The material forming the internal flange across the end of the 
bed is now suspended from the top of the boss and the work is com- 
pleted by placing in upon the bottom board and up to the end of the 
box, material to form the metal thickness around the holding down 
bolt. It is also necessary to place a rib on the center line of the bed. 
This rib separates the core into two parts. The box is rammed up 
in a reverse position to that shown in the drawing, Fig. 65, that is, 
upside down. 

Core A9 which forms the portion of the space between the side 
of the bed and the crank-pit and extends from the core A8 to core 
A3, with the exception of the distance occupied by the thickness of 
the ribs, is the next one to be constructed. The ribs separating the 
cores A8 and A9 are on the same angle as the end of the crank-pit. 
The box is made of rectangular form, and contains a section of the 
internal flange along the side of the bed, and one-half of the holding 
down bolt boss, the other half being formed in core A3. With the 
exception of the piece to form the angle at the end this box is complete. 

We next turn our attention to cores All, A12, and A13. These 
three cores are all made from the same box. Owing to the fall or 
pitch of the metal supporting the cross head guide, the bottom of 
the box requires considerable change for each core. The box con- 
sists of a frame with bottom board, and is gotten out in length equal 
to the width of the bed, plus a convenient allowance for dropping in 
the lagged up forms, which conforms to the flaring sides at the 
bottom of the bed, as shown in cross section on the line EE, Fig. 72. 
The frame is made of sufficient depth to permit the use of filling in 
pieces upon the bottom board. These pieces give the outline of the 
cross section of the metal, as well as the proper pitch or fall toward 
the cylinder end, as shown in the elevation of the bed Fig. 65. The 
width of the frame is made to correspond to the widest core, which 
is A12, plus the thickness of the rib, the half thickness of the rib 
being placed in each side of the box. As cores All and A12 do not 



HEAVY BED PATTERNS 



59-1 



extend the full width of the bed, but only to the metal thickness 
separating this part of the bed from the bracing member, it is neces- 
sary to use a stop off board to give the core its correct length. The 
interior flange is placed in at the top of the frame and supported by 
the lagged up form at the end. The changes required for All and 
A13 can readily be seen by studying the cross sections and Fig. 65. 
Core A14 is of triangular shape and forms the interior of the 
bracing member and a short section of the flarinq; side of the bed at 



Fig. 88. Methods of Molding 

Cylinder End of 

Pattern 




the intersection of the two parts, as shown in the plan view of bed 
Fig. 65. The core is made entire, being rammed up in a frame with- 
out a bottom board. The top of the frame corresponds to the angular 
side of the bracing member. The material forming the internal flange 
around the bottom of the bed is secured to the side of the box, while 
the metal thickness around the oblong opening formed by core A15 
is provided for by an oval block secured to a support across the top 
of the frame. 



60-1 ENGINE PATTERNS 

Method of Molding 

The method of molding is known as the bedding in process, 
that is, the pattern is rammed up in the floor and the mold subse- 
quently skin dried. The process may embrace some points of interest, 
but owing to the limited space, we will discuss only that part shown 
in the three views in Fig. 88, which, of course, will be molded in 
the reverse position. This shows two ways of arranging the mold 
at the top or cylinder end of the pattern. It will be readily seen that 
the diameter of the cross-head housing core at WX is greater than 
the width of the mold at YZ, which will not allow the core to be 
placed in position in the mold without coring or cheeking off the two 
sides of the mold. There are two ways in which this is usually 
accomplished. First: Core prints may be attached extending to the 
rounding of the corner of the pattern, as shown in the full lines, and 
a dry sand core used. The end of the pattern will be cheeked off, 
as shown by the dotted lines. 

Second: The cheek may be made in two parts jomed aiong the 
line VV, shown in a view at the right, and letting it extend around 
the sides of the pattern to the combined width of the core print and 
cheek shown. Of course, when this latter method is employed the 
core prints are not attached. 



SECTION II 

MOLDING IN CORES 

CHAPTER I 
MULTIPLE CORE MOLDING 

As the name implies, this process consists in the grouping or 
stacking together of a number of cores containing impressions of 
the object to be cast and so arranged that they can all be poured 
from one gate. This method of core molding is especially adapted 
to small steel castings, for in most steel foundries the facilities for 
pouring light pieces are not of the best. In other words, in steel 
foundry practice the pouring is usually done from a large bottom 
pouring ladle and hence it is difficult to pour small molds. The 
method is also especially applicable in cases where there is not a 
sufficient number of pieces required to warrant the fitting up of a 
molding machine. 



Fig 1. Coupling Pin 

This method of core making is remarkably well illustrated by 
considering the equipment necessary for making the coupling pin 
shown in Fig. L Another advantage of selecting this particular piece 
is that is affords an excellent example of the making of plaster pat- 
terns for the metal core boxes, these plaster patterns being made 
from the original wood pattern of the pin by a reversing method. 

A plan, elevation and cross section of the bottom plate of the 
metal core box used in forming one-half of the core are shown in 
Fig. 2, while Fig. 3 shows a plan elevation and end view of the bot- 
tom plate used in forming the remaining half. 



2-1 1 



MOLDING IN CURES 



The metal plates which form the sides and ends of the core and 
which are secured to the bottom plate by means of pins in the position 
shown in cross section on the line W in Fig. 2 and in dotted lines 
Fig. 3 are illustrated in two views in Fig. 4. In the illustration the 
frame is shown as arranged for the bottom plate illustrated in Fig. 3. 
The piece for forming the runner in the core is shown at X and in 
this case must be made of the length shown at Y, Fig. 3. The frame 
used upon the bottom plate shown in ¥ig. 2 is of the opposite hand 
in respect to the runner X only, and this runner has to be of a length 
equal to Z, Fig. 2. A pair of the half cores which have passed 
through the operation of ramming and drying are shown ready for 
jjasting together in Fig. 5. 




Fig. 2. Bottom Plate for ForminR one Core 

The arrangement for cores as they would appear when stacked 
and bolted together ready for casting is shown in Fig. 6. This simply 
consists of a cast iron bottom plate provided with lugs to receive 
holding down bolts and of sufficient length and width to receive four 
complete cores. The cores are stacked up to the desired height, say 
four feet in the case illustrated. The holding down bolts are set in 
position, the two top plates applied across the cores and the whole 
securely bolted together. To prevent the cores from separating 
lengthwise, two clamps can be dropped over the top plates and wedged 
up as shown. The runner is next placed in position, when the mold 
is ready for the metal. 



MULTIPLE CORE MOLDING 



3-II 




Fig. 3. Bottom Plate for the other Core 

One point that is worthy of notice in this connection is that this 
process works remarkably well for steel, on account of the fact that 
steel solidifies so quickly that it has very little tendency to work into 
the joints between the cores and before the upper part of the mold 
is filled all of the runners in the lower part have chilled so that part 
of the mold is never subjected to the fluid pressure of a column of 
molten steel equal to the height of the pile of cores. If this method 
were used for gray iron castings it might be found necessary to place 
curbing about the molds and ram in sand between the curbing and 
the cores. 

Making the Core Boxes 

As the frame which forms the sides and ends of the cores as 
shown in Fig. 4 is a very simple casting which is molded from a 
wooden pattern, its production will not be taken up in detail, but we 



(T 



p^ — 



Itunner JC 









i^ 




Fig. 4. Side Plates for Core Box 



Fig. 5. Section of a Pair of Cores 



4-II MOLDIXG IN CORES 

will discuss only the method required for the production of the plaster 
of paris bottom plate patterns from the original wood pattern. The 
wooden pattern is shown at the right of Fig. 7, while to the left is 
shown the board upon which the pattern is placed for making the 
first cast. To allow the pattern to lie flat on the board a depression A 
is cut out to receive the lower shoulder. The pattern is then placed 




Cast Tron.£late 



M" 




Fig. 6. Stack of Cores ready for Casting 



Fig. 7. Wooden Pattern and Pattern Board 



in position and the material B, C and D placed about it to bring the 
parting in the right position and this is secured to the board by screws 
from the under side, as the pattern is also. The whole is then given 



^<MUline of Frame 




Outline of Frame 

Fig. 8. Board with Pattern in Place 

a heavy coat of shellac. Fig. 8 shows the board with the pattern in 
place ready for making the first plaster cast. 

A light wooden frame or box, the inside dimensions of which 
correspond to the length and width of the desired core as shown in 



MULTIPLE CORE MOLDING 



5-II 



Fig. 5, and with a depth of about 3>4 inches, is nailed together and 
secured upon the board, as indicated by the dotted Hnes. The board 
and pattern are then well oiled or greased, after which attention is 
given to the mixing of the plaster. 

To insure good results, very fine, or as it is sometimes called,, 
dental plaster, should be used. Care should be taken to see that all 
lumps are broken up, and to accomplish this it is a good plan to run 
the plaster through an ordinary flour sieve before mixing. The 
plaster should always be kept inclosed and in a dry place. Two 





Fig. 10. Second Cast 
made from the First 



Fig. 9. First Plaster 
Cast 



Fig. 12. Plaster Pat- 
tern made from Cast 
Fig. 9 



Fig. 11. Plaster Pat- 
tern made from Cast 
Fig. 10 



persons should work together when doing the mixing, so that it may 
be accomplished quickly. First, fill the can in which the plaster is to 
be mixed with the desired amount of water and introduce a small 
quantity of plaster. The plaster should be introduced by one person, 
while the other stirs the mixture. If it thickens too fast, more water 
should be added. It should be mixed to the consistency of heavy 
cream. 

When pouring care should be taken to see that work sets level 
and the plaster should be poured as quickly as possible over the entire 
surface. If the plaster has been mixed properly the screws can be 
taken out and the frame and bottom board removed in about 30 min- 
utes. Should the pattern or material forming the parting stick in the 
least, it can generally be loosened by rapping it lightly. 

Blow holes are apt to appear in the plaster and when encountered 
they can be filled up with either plaster or wax. 

If this operation has been successfully accomplished the plaster 
cast will appear as shown in Fig. 9. Fig. 10 shows the second cast 



6-II 



MOLDING IX CORES 



which has been obtained from the first cast shown in Fig. 9 with the 
aid of the wood pattern and a Hght frame about 4^^ inches in depth. 
In carrying out this work the face of the first cast is shellacked and 
then covered with a good application of oil or grease. The pattern 
is then ])laccd upon the first cast in the depression left vacant by it, 
the cast is placed upon the level board, the frame set over it, and the 
mixing of plaster and pouring proceeded with, as in the former case. 




Sectio/i K'K Section Z-L 

Figs. 13-14. Sections of Casts ready to receive the Plaster 

It is next necessary to cast the two plaster patterns, as shown 
in Figs. 11 and 12. The plaster pattern shown in Fig. 11 is produced 
from the plaster cast shown in Fig. 10, while the plaster pattern shown 
in Fig. 12 is produced from the plaster cast shown in Fig. 9. 

As the plaster casts now made are of the same length and width 
as the desired cores, provision must be made for the additional width 
or projecting edge E, Figs. 11 and 12. This projecting edge around 
the four sides is intended to receive the flange of the frame, as shown 
ir Fig. 4. This is accomplished by placing the material F, Figs. 13 
and 14, which in thickness is equal to the width of the flange, on the 
frame shown in Fig. 4, around the four sides of the plaster cast. The 
entire arrangement is then surrounded with a light frame G, Figs. 13 
and 14. Cross sections on the lines KK and LL of the two plaster 
casts shown in Figs. 9 and 10, as they would appear arranged ready 
to receive the plaster, are shown in Figs. 13 and 14. 

As in the previous case, to prevent the plaster sticking, grease 
or heavy oil should be used freely over the entire surface. 

At the completion of the casting of the plaster patterns, they are 
removed from their casts or forms and a coat of shellac applied to 
the face. They are then backed out to give the required metal thick- 
ness. A good portion of this surplus plaster can be avoided by placing 
blocks H and I upon the bottom board as shown in the cross sections, 
Figs. 13 and 14. The patterns are finished with two coats of shellac. 
The gate J, Figs. 2 and 3, is next worked out of a piece of wood and 
attached in the correct position, being secured with shellac. The pat- 
terns are then sent to the iron foundry. When the castings come 
back from the foundry they are cleaned up and finished in the usual 
manner, the plates being doweled or pinned to the frames shown in 
Fig. 4. 



LARGE WORK IN CORES 7-II 

CHAPTER II 

STACKING CORES FOR LARGE WORK 

When it is necessary to cast a considerable number of large steel 
castings from special heat which requires practically all of the metal 
from one charge of an open-hearth furnace, the question of floor space 
for the large molds is often an important one and the foundryman 
frequently finds himself in a quandary as to the best method of getting 
out of the difficulty. One method of solving this problem is shown 
in this chapter and consists in simply stacking or piling upon one 
another a series of cores which form the molds for the rings or pieces to 
be cast. Of course, it is necessary to provide a proper arrangement of 
gates so that the rings may be cast from the same runner, and also 
to provide risers. While this method of molding will not under ordi- 
nary circumstances be found the cheapest on account of the expense 



10 Cored Holes Eqvalhi Spacerl 




Inverted Plan 



Fig. 15. Section of Ring Casting 



of making the cores, etc., it will be found that the extra expense in- 
curred will not condemn the method, owing to the saving in floor 
space, etc. The rings illustrated are about twelve feet in diameter and 
have a cross section as shown in Fig. 15. 

A cross section of one of the bottom cores, together with the box 
in which they were formed, is shown in Fig. 16, the core box being 
shown in the plan and cross section. In like manner in Fig. 17 is 
shown a cross section of one of the top cores together with the plan 
and cross section of the core box in which it was formed. It will be 
observed that a male and female joint is formed upon the two cores, 
this being necessary to locate them in position one upon the other. 

Setting the Cores 

In constructing the mold a hole is dug in the floor to the required 
depth. The spindle with the sweep attached is next located in its proper 



8-II 



MOLDIXG IX CORES 



position and a level bed struck off. The sweep is then raised to the 
required height and the lower half of the first series of cores placed in 
position. The proper diameter of the ring is maintained by setting 
the cores to the gauge A which is attached to the sweep, as shown in 
Fig. 18. 

At the right in Fig. 18 is shown the setting of one of the bottom 
cores, while at the left of the spindle is illustrated the operation of 
sweeping off the bed to receive the cores. 






mm' J, 




^Trry 




M 




\ Section of 




^i 

% 




\ Bottom Core 

4»^u(( Slot 

^^ Corea 




mil 


B 


-' 


Sec 


tion B- 






/I ( T) Section of 
Top Core 



Fig. 16. Section of Bottom Core and Box 



Fig. 17. Section of Top Core and Bo.x 



The upper series of cover cores is next placed in position, being 
guided by the male and female joints. A light thickness of sand is 
next applied over the upper surface, the sweep is raised up and the 
sand applied struck off level to receive the bottom cores of the second 
set. The second set of cores are located with the aid of the gauge A 
as in the first case. In this way the work is proceeded with until all 
three of the series of cores forming the complete mold have been 
placed in the proper position. 

The runner is centrally located and each ring receives metal from 
four gates placed at right angles to one another, as shown in Vig. 19, 
which illustrates two half sections of the mold. The section at the 
right being taken through the gates illustrating the manner of gating, 
while the section at the left is taken through the risers and illustrates 
the manner of attaching the same. It will be noticed that the risers 
are placed on the outer diameter of the rings. 

After the three scries of cores are set in position the molder has 
to turn his attention to the placing of the runner and gate cores, the 
arranging of the risers. This work being done during the backing up 
of the mold with sand, as shown in the cross section of the completed 
mold. 

Sand is first rammed inside and outside of the cores to the height 
of the gate openings on the inner diameter of the cores and the risers' 
openings on the outer diameter of the first series of cores. 



LARGE WORK IN CORES 



9-II 



The runner and gate cores are shown in detail in the upper part 
of Fig. 19 and also in position in the lower part of the figure. After 
the first set of cores for the gates are placed in position the first one 
of the block cores for the runner is placed in the center and the ram- 
ming in of the sand backing proceeded with until the openings in the 




Fig. 18. Spindle Rigged for Setting Cores 

second series of cores are reached when the gate cores and next block 
for the runner core are set as in the first case. When the backing of 
sand reaches the top of the upper series of cores a level bed is struck 
oflf to receive the holding down plates. 

The risers are formed by the use of the riser block shown in the 
upper left hand corner of Fig. 19. The runner and risers are next 



Riser Block 




Fig. 19. Section of Mold 



carried up to the desired height and the weighting down of the cores 
attended to. It will be observed that the riser for the lower ring is 
not carried to the same height as the others on account of the fact 
that it is not necessary to do so. The riser for the first ring is ter- 



lO-II MOLDIXG IX CORES 

ininated at the surface of the mold as indicated by the words "bottom 
mold." The riser for the second ring is terminated at the dotted line 
designated "middle mold," while the riser for the upper mold is carried 
up to the same height as the gate. When the metal in the first riser 
has almost reached the surface of the mold the riser is covered with a 
plate and weighted down. In like manner when the metal reaches the 
top of the second riser it is covered and weighted. 



ROUND FLASKS IN CORES 
CHAPTER III 



11-11 



CASTING ROUND FLASKS IN CORES 



The accompanying illustrations show one method of casting round 
flasks of large diameter in cores which has given very satisfactory 
results, and a saving in pattern expense, as well as in the floor space 
required for pattern storage. A plan and cross section of a portion 
of the required flask is shown in Fig. 20. It will be noted that there 
are two lines of cored bolt holes about the flask and a sand strip on 
the inside of the top and bottom. In most cases, four trunnions are 
cast on each flask, one of these being shown in Fig. 20. 




GATE AND RUNNER 







Fig. 21 



Fig. 20. Plan and Section of a portion of 
the Pattern 

Fig. 21. Cores in Position 

Fig. 22. Segment for Setting Cores 



A cross section through one side of the assembled cores is shown 
in Fig. 21, illustrating the manner in which the cores are placed to- 
gether. In making up the mold a hole is dug in the floor to a depth 



12-11 



MOLDING IX CORES 



equal to the height of the cores and with the aid of straight-edges a 
level bed is struck off. 

With the segment attached to and revolved about the stake as 
shown in Fig. 22 an offset shown at A, Fig. 21, is rammed up to assist 
in setting the cores. 

The number of separate pieces or cores is governed by the diameter 
of the flask. The circle formed by the offset is divided by four equi- 
distant lines, and the centers of the four cores containing the trun- 
nions are set to these lines. 




Fig. 23. Core Box for Outer Cores 
Fig. 24. Core Box for Trunnion 
Fig. 25. Core Box for Inside Cores 



Fig. 25 



At the completion of the setting of the remaining cores, sand is 
banked and firmly rammed around the inside cores, as well as in the 
space between the outside of the cores and the wall of the hole or pit. 
To avoid filling the entire space inside the cores with sand, a flask of 
convenient diameter and height can be placed within the inclosure 
formed by the cores and the space between the flask and the cores 
rammed firmly with sand. 

The core box used in forming the outer cores is shown in Fig. 23. 
The trunnion and rib portions are loose from the box, allowing these 



ROUND FLASKS IN CORES 13-11 

parts to be removed when the plain cores are being made. The bolt 
holes are spaced off accurately, and taper prints are set to receive the 
separate cores for these holes. By giving the core prints ample taper, 
they can be rigidly attached to the box. A covering core is used in 
connection with this box to form part of the trunnion, this portion of 
the box being parted as shown with the core print above and extendnig 
to the top of the box. 

When the print has been withdrawn the core made in the core box 
shown in Fig. 24 is placed in this impression so as to close the opening 
and form the flange or outer end of the trunnion. 

The core box used in forming cores for the inside of the mold is 
shown in Fig. 25, and it will be noticed that loose wedge pieces are 
used to form the radial ends of the cores. To simplify the construc- 
tion of the box and facilitate the drying of the core, the open side of 
the box is made flat in place of conforming to the diameter of the mold. 
Gates are filed in the tops of these cores at different points, and runners 
built up as shown in Fig. 21. 



14-11 



MOLDING IN CORES 
CHAPTER IV 



MOLDING A THREE-WAY COCK 

A three-way cock or plug valve of the design shown in Fig. 26 
is in many ways a difficult casting to mold. If molded in green sand 
it would require a three-part flask in addition to the cores. 

In most cases this piece can be molded in cores more quickly 
and cheaper than in any other way. 

In Fig. 26 the central view shows a plan of the cock, the left hand 
figure a side view and the right hand figure a section on the line X, X. 




Section X-X 



Fig. 26. Three-way Cock 

This design of valve is also sometimes made with an open bottom 
A, which is subsequently covered with a plate secured to the cock. 

To a patternmaker or molder the various disadvantages and diffi- 
culties in connection with this job will be readily appreciated, but 
without stopping to discuss these we will proceed to describe one 
method that has proven very successful in many cases. 

The cores for the mold are shown in Fig. 27. The upper view 
is a horizontal section taken on the line U, U, while the lower view 
shows a vertical section taken on the line Y, Y. The outer part con- 
sists of three cores B, C and D, which are joined on radial lines at 
E, F and G. 

The center core H and the core for the passage on the line G 
are made in one piece, while the cores for the passages E and F are 
made separate as shown at I and J. 

When assembling the mold the cores C and D are placed together 
with the center passage core H in place with its projection for the 
passage core between the cores C and D. This holds the core H in 
place and locates it correctly. 

Before the core B is set the cores I and J must be set into the 
center core H and held in place until the core B is located. To assist 
in holding the cores I and J in place they are made long enough so 



A THREE-WAY COCK 



15-11 



that their ends project as shown at K. These projected ends may be 
held or blocked up, while setting the core B. 

When the parts have been assembled a flask is placed around the 
group and a backing of sand rammed in. 

The core boxes are made as shown in Figs. 28, 29 and 30. The 
box for making the large cores B, C and D is shown in Fig. 28, the 
upper view being a plan and the lower view a section on the lines 
Z, Z. The checks L, L are made loose in the box as are also the 
diagonal pieces M, M, which carry the patterns P, P. When making 
a core the box is rammed full of sand, the blocks L taken out and 
the depressions left filled in with green sand. The box is then rolled 




Fig. 28. Core Box for Body 



Section 1'- 1' 

Fifif. 27. Cores for the Mold for a Three-way Cock 

over and the main gate drawn out through the side of the box (of 
course the gate is only required in one of the three cores). After the 
gate has been drawn the frame is removed and the blocks M, M 
carrying the patterns P, P drawn. This leaves the gate N exposed 
to be drawn. 

In order to make the center and passage core H entire as shown 
in the assembled mold, two half core boxes, one of which is shown in 
Fig. 29, will be required. The core print in the bottom of the center 



1&-I1 



MOLDING IN CORES 



portion of the box is left loose to be drawn from the core after the 
latter has been turned over onto the core plate. 




F 
Fig. 60 

Fig, 29. Box for Central Core with one Branch 
Fig. 30. Box for Branch Cores 



Two other half boxes, shown in Fig. 30, are necessary for making 
the cores I and J shown in Fig. 27. The reason both half boxes are 
required for this purpose is on account of the taper of the center 
core H. 



COVERING CORES 17-11 

CHAPTER V 

THE USE OF COVERING CORES 

There are a very great number of ways in which covering cores 
can be used, but the accompanying illustrations cover the principal 
uses of this class of cores. 

Covering cores are also frequently called slab cores, and can often 
be set without the aid of a core print. 

The use of the covering core frequently saves a three-part flask, 
or the adoption of a more intricate cored mold and expensive patterns. 




^ Core Side ***'''.C^O J'in.34 



Fig. 31. Covering- Core for Casing 
Fig. 32. Stuffing Box Pattern 



Fig. 33. Pattern and Mold for a Double Bearing 
Fig. 34. Mold for a Shrouded Gear 



In some cases, especially in a deep setting, the covering core may be 
objected to by some foundrymen, on account of the difficulty of remov- 
ing any sand which may fall into the mold during the drawing of the 
pattern. When the covering core is used in the cope, this objectionable 
feature is done away with, as the core may be placed in the depression 
left by the core print previous to or after the closing of the mold. 
When the core is used in this way, of course it is inserted through the 
cope and weighted or wedged down. 

The application of a covering core to a mold for a casing or hood 
is shown in Fig. 31. In this casting there is a very light metal thick- 
ness and the advantage of the suspended core in regard to venting and 
also setting, in the production of a sound casting will be readily seen. 

The molding of such a piece as this with the ordinary dry sand 
core would usually make it necessary to cast or mold the piece in a 
reverse position and this would not, as a rule, give good results. When 
a metal pattern is used which leaves its own core it is possible to mold 
the bowl in a reverse position successfully. 



18-11 



MOLDING IN CORES 



A cylinder head and stuffing box pattern are shown in Fig. 32, 
together with a core print for the covering core attached. This arrange- 
ment gives a very simple pattern and mold. The core print is drawn, 
together with a part of the pattern A, during the ramming up of the 
mold, and the slab core interposed in place of the core print. The 




Fig. 35. Covering Cores with Curved Ends 

ramming of the mold is then completed by the ordinary method. This 
operation is described and illustrated more fully in the next example. 

The covering core method as applied to a double bearing is illus- 
trated in Fig. 2>2>. At the left is shown the end view of the bracket 
portion of the pattern, illustrating the general construction of the 
bracket and showing the parting line ABC. At the right is shown 
a longitudinal section of the partially completed mold with the cover- 
ing core in place. 

In making the mold the pattern is placed upon the board and 
rammed up to the top of the core print in the ordinary manner. The 
core print, with a portion of the bearing above the line A B C, is next 
withdrawn from the sand and the covering core placed in the depres- 
sion left by the core print. The balance of the flask is now rammed 
up, struck off and rolled over in the ordinary manner. The cope is 
then placed in position, the ramming completed, and the balance of 
pattern drawn as usual. 

The covering core as applied to a shrouded gear is shown in Fig. 
34. The illustrations show the pattern rammed up with the core in 
place and the flask rolled over ready for placing the cope in position. 

Many circular pieces of work in the foundry can be covered with 
slab cores to save the ramming up of the cope. This method is shown 
in Fig. 35. Usually the ends of the cores radiate to the center. When 
this is the case unless they are made to the proper diameter the ends 



COVERING CORES 19-11 

will not fit together without filing and fitting of the cores. As these 
cores are frequently kept in stock, they are a source of much trouble 
to the molder. This trouble can be readily done away with by making 
the end of one core convex and the corresponding one concave, as 
shown in Fig. 35, where the curved line ABC represents the junction 
between the adjacent cores. By this arrangement the ends of the 
cores can be kept together while they are adjusted for almost any 
radius of mold. 



20-11 



MOLDING IN CORES 
CHAPTER VI 



T SLOT AND NAME PLATE CORES 

The use of chaplcts for holding down the cores in floor plates, 
etc., is generally a source of considerable trouble, but this difficulty 
may be done away with by constructing the cores as shown in Fig. 36. 
At the left is shown the pattern with a core print attached and the 
outline of the core shown by dotted lines. To the right is shown a 
cross section of the mold, with the core in place. 



Core Print Core 




Fig. 36. T Slot Cores 

It will be noticed that the core print is wider than the head of the 
T slot and hence when a core of this section is set into the depression 
made by the core print and the metal flows into the mold, there will 
be more area exposed to the metal along the width A than along the 
width B, in other wofds, the surfaces D are wider than the surfaces C, 



m 



Print portion 
of Cot 



Scvtion of ?Iol<l 



Fig. 37. T Plot Core 



Section of Core 



hence the metal which exerts a lifting force along the overhanging 
portions C will be more than balanced by the metal bearing down on 
the portion D. With cores made and set in this manner, no chaplets 
are necessary. 

These cores are even better illustrated in Fig. 37. This illustration 
shows a form of core which is used by the author with good results. 
At the left of the fisrure is shown a section of the mold with a core in 



NAME PLATE CORES 



21-ir 



place, while at the right there is a detailed drawing of the cross section 
of the core. 

The lettering is the same as that in Fig. 36. Some persons have 
claimed that cores of this kind would not stay down if no nails were 
used. The author has watched every step of making and pouring the 




-^-7+^ 



G 



FIG. 39 

Fig. 38. Core Print for Name Plate 
Fig. 39. Core Print Box for Name Plate 

mold many times and knows that they will work if there is no opening 
under the base of the core into which the metal can flow. If metal 
flowed under the base of the core it would be lifted. But any good 
molder will see that the sand is slicked up to each side of the base of 
the core. 

Figs. 38 and 39 show a method employed in placing name plates 



22-11 MOLDING IS CORES 

upon engine beds, etc., and one which insures their non-removal except 
by chipping. The method consists in the use of a slab core of any form 
made from a core box upon the bottom of which is placed the desired 
lettering. 

Fig. 38 shows the core print, in this case of an elliptical form, and 
secured to the pattern by two loose dowels of different diameter as 
shown, in order to avoid placing the core print in the reverse position. 
A marker "B" is also required upon the print and in the core box, to 
insure placing the core in its correct position in the depression left 
vacant by the core print. 

Fig. 39 shows the general arrangement of core box which is 
parted on the lines "C C" and "D D." 

The frame or print portion "E" having been gotten out to conform 
to the core print shown in Fig. 38, it is placed upon the bottom board 
"F" and secured with dowels, and its elliptical outline is scribed 
thereon. The surface inclosed by this outline is now backed out or 
depressed to the required depth "G" (which is usually the thickness 
of metal letter used) and the metal lettering is attached in the ordinary 
manner. 



A SMALL STEEL CASTING 23-11 

CHAPTER VII 

MOLDING IN CORES 

In many cases, and especially in the case of steel castings usually, 
better results can be obtained from a dry sand mold, and frequently 
this can be obtained more easily and economically by making suitable 
core boxes and forming the mold of cores. 

A Small Steel Casting 

Fig. 40 shows a required casting 10 inches in length which would 
be rather difficult to mold from an ordinary pattern withou*^ an exceed- 
ingly complicated mold. Fig. 41 shows a plan of the core box and a 
section of the pattern on the line A-B, Fig. 40. 




Fig. 41. Plan of Core Box 



Fig. 40. Casting to be made in Cores 

Fig. 42 shows the manner in which different parts of the pattern 
are set together. The pattern is made in five parts, as indicated by the 
letters V, W, X, Y and Z. In Fig. 42 the pattern is shown half in 
section and half in elevation, so as to show the manner of parting the 
different pieces of the pattern. The half section is taken on the line 



24-11 



MOLDING IN CORES 



E-F, Fig. 41. It will be noticed that the pattern is set in to the bottom 
board holding the parts in position. 

The core box is made deep enough to allow a sufficient amount of 
sand above the pattern, and the core print U is placed upon the pattern 
as shown in Fig. 42. The height of the core print is equal to the 
amount of sand allowed above the pattern and the diameter of the 
small end should be large enough to allow the part V of the pattern to 
be drawn with the print. 

In making a core the pattern is placed in the core box, rammed up 
and struck off. The core print U and portion of the pattern V are then 
drawn, after which the core box is rolled over and the parts W, X, Y 
and Z drawn from the other side. 




Figr. 42. Arrangement of Pattern 



SEGTION A-B 
Fig, 43. Section of Pattern 

Fig. 43 shows sections of the pattern on the lines A-B and C-D. 

A block the form of the core with a depression corresponding to 
the core print U, not shown, is used as a pattern to make a mold to 
receive the core, the mold being gated through the portion of the cope 
fitting the space U. 

When a great number of castings are required a box can be 
made large enough to receive a number of these cores, and rammed up 
with depressions in the drag. A runner can be rammed up in the 
center one in place of one of the patterns and the surrounding ones 
gated from this. This manner of coring will be found very convenient 
in small steel castings where a dry sand mold is desired. 



PROPELLER WHEEL IN CORES 
A Small Propeller Wheel 



25-11 



Small propeller wheels may also be molded in cores, either dry 
sand or green sand, by using a core box of the form shown in Figs. 
44 and 45. 

One advantage of this method is that it assures the fact that the 
blades are as nearly alike as it is possible to make them, which is im- 
portant. Usually in molding a pattern of this description a follow 
board is used, while that part of the core box containing the back 
of the blade is rammed up. The face of the follow board can be de- 
veloped and built as a propeller blade. As a blade contains but a small 
portion o/ the area of the surface of the box, it is not necessary to 
make a follow board the full dimensions of the size of the box, but just 
wide enough to form a joint all around the blade. The remaining por- 
tion of the surface can be cut away to any convenient angle, as shown 
Fie. 45. 




Figr. 4b. Section of Core Bo.x for Propeller Wheel 



Fig. 44. Plan of Core Box for Propeller 



By building the follow board first, so that its face represents a 
portion of the face of the blade it can be used in building and laying off 
the pattern, the pattern being built by gluing strips together, and work- 
ing off back to the proper form. 

If the pattern is made first, the follow board can be made of 
plaster of paris, the pattern being used to give it the proper shape. 
Plaster being used for very small wheels only. 

In molding patterns of this description by this method, iron skel- 
etons or core irons wnth suitable lifters must be provided for both parts 
of the mold for lifting out the core. 

When making a mold, the top part of the core box containing 
the back of the blade is rammed up first with a core iron or skeleton 
properly placed, the core box is then rolled over, the follow board 
removed, the parting prepared and the balance of the core box rammed 
up with the core iron or skeleton in place. After the ramming is com- 



26-11 



MOLDIXC IN CORES 



pleted, the core box is removed, the cope part of the mold Hfted off 
and held suspended while the pattern is withdrawn and the mold fin- 
ished. A level bed is then prepared and the drag part of the core is 
placed upon it and the cope part on top of the drag portion. These 
operations are repeated for each of the succeeding blades thus forming 
a complete circle. 

Of course in the case of dry sand cores they must be baked before 
they are placed upon the bed. 

After the cores are placed in position upon the bed an open flask 
or box or a metal curbing is placed around them and the space between 
the cores and the box or curbing rammed with sand to form a backing. 
The cores must also be weighted down. 

A Large and Crooked Steel Casting 

A large steel casting weighing 8,000 pounds is shown in Fig. 46. 
This is a cutter head used on a large centrifugal dredge. 




Fig. 46. Forge Steel Casting 



Fig. 47. Plan of Core Box 



From the form it will be seen that this would be a rather difficult 
piece to i)roduce in an ordinary green sand or dry sand mold. But by 
molding in cores in a manner similar to that used for small propeller 
wheels, the work was accomplished with ease. 

Fig. 47 shows a top view of the core box, with the pattern for one 
of the five arms in place. Fig. 48 shows the core box with the front 
removed and shown at the left. The pattern is shown in place in the 
portion of box on the right. 

In making one section of this mold in the core box, that portion 
of the core which contained the back of the blade was rammed first, 
the core iron or lifting plate being ])laced near the bottom of the box. 



A STBEL CUTTER HEAD 



27-11 



A parting was made along the edge of the blade as the ramming pro- 
gressed. This parting was then covered with parting sand, a lifting 
iron introduced for the upper portion of the core and the upper portion 
rammed. The front of the box was then removed and the sides 
drawn back, leaving the core free. The top or cope part was then 
lifted off and held suspended while the pattern was drawn and the 
mold finished. It was then placed back in position and the whole 





Fig. 48- Elevation of Core Box with Front removed Fig. 40. Block or Model of Pattern 

core shoved into the oven to be dried. For convenience the core was 
made upon a car so that it did not have to be removed from the 
car to introduce it into the oven. 

After the five sections were completed, a pit was dug, a level bed 
swept up, the sections placed together, provision made for suitable 
gating and for sinking heads. The whole was then backed up with 
sand thoroughly rammed. 




Fig, 50. Plan of Supports on Building Board 

The pattern for this job was made as follows : Owing to the 
angular form of the blade it was impossible to lay it out from the 
drawing in a reliable manner and hence a block or model was turned 
to scale, as shown in Fig. 49. The diameter and form of this block 
corresponded with that of the cutting edge except that it was made 



28-11 



MOLDING IN CORES 



to a smaller scale. The outline of the cutting edge was then laid off 
on this block and the material cut away so as to give the sections A, 
B, C, D and E. The whole surface between these sections was cut 
away to represent the under side of the blade. The width of these 
sections was laid off and these points connected with a flexible rule or 
strip and this line was sawed perpendicular to the base, giving the inner 
outline of the blade. This outline was then transferred full size to the 
building board and perpendicular supports erected as shown in Fig. 
50. these supports conforming with the angle of the blade at the 
points A, B, C, D and E, Fig. 49. A half hub was made and secured 
in its correct position. The portions of the hub outside of the lines 
A-B and A-C Fig. 50, were afterwards cut away to fit the core box. 
The pattern was built by fitting pieces over the supports as shown 
by the parallel lines in Fig. 50. These being glued together and to 
the hub, and the back worked off. The pattern was subsequently 
parted on the lines A-B and A-C and the portions of the pattern which 
fell outside of these lines were secured to opposite sides of the core 
box, as shown in Figs. 47 and 48. 

Molding Rope Sheaves 

A method of molding rope sheaves having wrought iron arms 
which are staggered in the hub is illustrated in Fig. 51, the left hand 
portion of the figure showing a section of the wheel and the right hand 
portion the method of making the mold. 




Fig. 51, Half Section of Rope Sheave and Half Section of Mold 

The core boxes for making the cores A and B for the upper and 
lower portions of the hub and the middle portions C and D are shown 
in Figs. 52 and 53 the boxes being shown in plan in the lower portion 
of the figures, and in section in the upper portion. These cores form 
the mold for the outside of the hub. An ordinary circular core formed 
in a regular core box is used for the bore of the hub. 

In Figs. 54 and 55 are shown the core boxes for forming top and 
bottom rim cores E and F and the jjroove core C. 



MOLDING ROPE SHEAVES 



29-11 



At A-B, Fig. 54, are shown two core prints used in the rim core 
box as shown in the section on the line Y-Z for forming the openings 
for the introduction of the wrought iron rods. It is necessary to 
change these prints for the top and bottom cores E and F, owing to 
the fact that the rods enter the rim at an angle and that this angle 
alternates with each succeeding spoke. 




Fig. 53 Fig. 52 

Fig, 52. Core Box for outside Section of Hud 
Fig. 53. Core Box for inside Section of Hub 
Fig. 54. Rim Core Box 
Fig. 55. Groove Core Box 



Fig. 54 



Fig. 55 



In making this kind of a mold, a level bed is struck up and the 
block or print bedded in to receive and set the hub core. The height 
of this is equal to H, as shown in Fig. 51. To a pin or spindle in the 
center a sweep is attached as shown in Fig. 56. 

This sweep is used for forming the bed which is to receive the 
rim cores E and the groove cores G. After this has been accomplished 
the lower section of the hub core A and the rim cores E are set, then 



P 



o 



.o \ 



Fig. 56. Sweep in place for Sweeping Bearings 



Fig. 58. Elevation of Forge Gear Bolting Face 



the rods which enter the core A are placed in position, the groove core 
G is set and the middle section hub cores C and D. 

Then the rods which enter the upper portion of the core are placed 
in position and the upper portion of the hub core B and the rim cores 
F placed in position. 

The hub cores C and D should be carefully pasted together, so 
that the upper and lower prints to receive the rods will come exactly 



30-11 



MOLDIXG I.y CORES 



between each other. Tlie bore core is set before the top core B is 
placed in position. 

After all the cores are in position, the mold is rammed up with 
green sand and weighted. In pouring a wheel of this description the 
rim is usually poured and allowed to cool before the hub is poured, 
as this lessens the strain caused by contraction and produces a sounder 
and better wheel. 

Molding Large Gear Wheels 

One method of molding a large gear in cores is shown in Figs. 
57 and 58. This method was applied to a cast steel split gear 15 
feet, 6 inches in diameter, 4 inch circular pitch, 144 teeth, and 16^ 
inch face, with a T section flange cast on one siae and joined to arms 
about midway between the hub and the rim. The entire gear weighed 
26.000 pounds. A drawing of a portion of the gear is shown in Fig. 
57 a section of the rim, of the T flange and the arm being shown. The 











SLAB CORE 


^' 


t.\v:-.7^;::;;\:-:A.Vl--SLAB CORE kv"'.'.v^£-- 


Wfi 




. 


J^:;,-^^^^^^^^ 








[:'::, ' : ' - . ' ' . r:-' - :"^i-:i) 






F?/';-'- 




■^'^H^.^--' - -- --^--' 


-lu^^^./^- ;-.::-'-:^^-\':-v-\"V:--^^^^^^ 






^V;::v;^ 






WM^ 


"l^^LAC 1. ,:-E ,■- " ;-^ ' . ■-- ";'- ~~-".,'' 




W^^M 


:Wi 


--"."":'■ -- - ■ : '1 ■ '^ 


■ • :.:•■- ■■.;.■ ■ .-: i ; :-.■■'. ^^ ■ ■ ■•• , • - . , 




' 















Fig. 59. Section of Mold 

dotted lines in Fig. 57 show the arrangement of the different cores 
which were used in forming the mold. In Fig. 58 a half elevation 
of the bolting face of the gear is given, showing the location of the 
bolt holes, which were cored, the construction of the hub, etc. 

A section of the mold through the center of one of the arms is 
shown in Fig. 59. It will be noticed that a slab core is used for cov- 
ering the joint at the hub, and also under the portion of the T flange 
opposite the arm. 

In making the core for the arm it was rammed level with the T 
flange, the face portion then drawn and the slab core placed over it, 
after which the box was rammed full. 

The arm core box was used for the upper and lower halves of the 
arm cores, the flange portion of the pattern being removed for the 
upper half of the core. The same box was also used for the half arm 
cores on the bolting line, a half arm with pads and core prints being 



A LARGE GEAR 



31-11 



used in the box as shown in Fig. 60. In this case part of the box 
was stopped off longitudinally by dropping in a board. 

The manner in which the cores for the portion of the T section 
flange between the arms were joined together is shown in Fig. 61. 

In beginning the mold a pit was dug as deep as the cores were 

T- 




Fig. 62. Spindle and Gauge Stick 
Fig. 63. Gauge Sticic for Teeth 



Fig. 57. Plan of Large Gear 



high, and a level bed struck off. With the aid of a spindle and the 
gauge sticks shown in ¥\g. 62 the arm and rim cores were set. 

The gauge stick shown in Fig. 63 and the templet of teeth shown 
in Fig. 64 were used for setting the teeth cores. The templet being 
used at the joints to see that the cores matched properly. This method 



32-11 



MOLDING IN CORES 




Fig. 64 

Fig, 61. Core for T Section Frame 

Fig. 64. Templet for Teeth 

Fig. 65. Special Core Boxes 

Fig. 66. Mold with some Cores set 



ic* 



Fig. 65 



A LARGE GEAR 



33-11 



of forming the teeth should be used only in cases where the teeth are 
to be finished by cutting. For cast teeth a segment containing a num- 
ber of teeth should be revolved about a spindle and the teeth rammed 
up in sections. 




Fig. 60. Arm Core Boxes 

A photograph of the mold taken during the setting of the cores 
is shown in Fig. 66. After the cores were all in place the space be- 
tween as well as that between the walls of the pit and the tooth cores 
was rammed with sand. 

In Fig. 65 is shown a photograph of some of the special core 
boxes used, which, together with the core boxes shown in Fig. 60, made 
all of the cores necessary for the different parts of the mold. 



34-11 



MOLDING IN CORES 
CHAPTER VIII 



THE USE OF NAIL CORES 

The use of nail cores in perforated cast iron strainers for the intake 
or suction end of pipes for pumps will be found a very simple and 
economical method of executing work of this character. While the 
manner of coring the holes is shown as applied to a strainer of cylin- 



/tfOOOOOOOOO" 
*0 OOOOOOOQo 

;oooooooooo 

lOOOOOOOOOO 
('GOOOOOOOOO 
V^vOOOOOOOOO o 
\Oooooooooo 



Fig. 67. A Strainer Head 



drical form as shown in Fig. 67, it can be applied to almost any form. 
It is particularly well adapted to flat work, such as strainer plates, fur- 
nace door baffle plates, etc. The pattern is parted longitudinally and 




Fig. 68. Pattern for Strainer Head 




Fig. 70. Mold for Strainer Head 



'!S'!^^f---i^'^wy<^\ 



^''^i^ddiii^&iiiiiiiM 



Fig. 71. Body Core for Strainer Head 




turned up as shown in Fig. 68. It will be observed that the core print 
is turned with a shoulder A, this being done to insure its proper setting 
into the mold. The mold having been rammed up in the ordinary 



NAIL CORES 



35-11 



manner and the pattern drawn, the nail cores, as shown in greater 
detail in Fig. 69, are set at proper intervals around the mold as shown 
in Fig. 70. The body core shown in Fig. 71 is then placed in position 
and supported by the nail cores. These cores are similar to those com- 





m^mmmm 






^Nail 



Figr. 69, Core Box for Nail Cores 



monly used in coring babbitt anchorage in bearings. They are formed 
in a multiple core box as shown in Fig. 69, the hole B permitting the 
nail to be inserted through the core before the box is turned over upon 
the plate. 



SECTION III 

SWEEP WORK 

CHAPTER I 
SWEEPING A PLAIN CYLINDER 

Cylindrical castings, such as that shown in Fig. 1, are frequently 
molded in loam by using sweeps which contain a radial section of the 
cylindrical portion of the casting. These sweeps are revolved around 
spindles and used to shape the material for the mold. Where cast- 



CASTlNia 



am 



m 



Fig. 1. Cylinder Casting 



ings are to withstand high pressure it is claimed that stronger and 
better castings having closer grain and denser metal can be made in 
loam than in green sand. 



2-III 



SWEEP WORK 



In this chapter we will treat both the rigs made in the foundry 
and those furnished by the patternmaker, as the exact method of 
handling the work cannot be understood in any other way. It is first 
necessary to make a foundation plate and a parting ring for support- 
ing the inside and outside portions of the mold. The foundation plate 
is shown in section in Fig. 2, and both the foundation plate and the 
parting ring in section in Fig. 4. These plates or rings are usually 
made in open sand molds by using segment patterns. 

After the rings or plates are completed, the foundation plate is 
leveled up with the spindle spider, or socket firmly imbedded below, 
as shown in Fig. 2. The upper end of the spindle is held in place 
by a bearing connected with braces which extend to the walls or to 
suitable supports built up outside of the mold. 



WALL BRACE 




■^^^^^55^^ 



GREEN SAND FLANGE 
LOAM 



Fig. 2. First Sweeping Operations 

The first sweep used in constructing the mold is shown at A, Fig. 2. 
In using any sweep it is always secured to the spindle in such a way 
that it is free to revolve about it. The sweep A is used to form the 
seat or offset parting, which is built up of brick with a loam facing 
sweep over it as shown. 

After the loam has been swept in place, the cleat B, together with 
the piece connected to it, is removed. This leaves an opening in the 
sweep having a form like a cross section of the lower flange of the 
desired casting. A green sand flange is then swept up on top of the 
loam, as shown in the right of Fig. 2. This is skin dried and is sub- 
sequently covered over with loam and brick to form the lower flange 
of the casting. The green sand can be easily removed when the mold 
is taken apart. Some molders prefer a pattern made for this flange, 
as shown in Fig. 3. 

After the flange has been placed or swept upon the seat, the part- 
ing ring for supporting the outer wall of the mold is placed upon the 
parting, as shown in Fig. 4. The sweep C is then secured to the 



A PLAIN CYLINDER 3- III 

spindle, as shown, and brick work built up upon the cast iron ring 
and loam placed upon it and swept off with the sweep C, as shown. 
The loam, of course, is given the proper form by revolving the sweep 
C about the spindle. 

Patterns are made for the branches, or nozzles, upon the side of 
the castings shown in Fig. 1. This pattern is shown in detail in Fig. 5 
and its setting in Fig. 4. These patterns are set by lines or are secured 
in their proper position by temporary supports and braces during the 
building of the outer portion of the mold. The core print A on the 
nozzle patterns is to form a seat for the covering core which forms 
the outer face of the flange and through which pass the cores for the 
inside of the nozzles. 




Fig. 3. Pattern for Lower Flange 

After the outer wall is completed and the flange and parting swept 
at the top, the sweep is taken out and this portion of the mold removed 
and dried in an oven. 

The main or central core is next swept up by using the sweep E, 
shown in Fig. 6. The lower arm F of the sweep is removed when 
the brick work has reached this height. The completed portion of the 
surface will act as a guide for the lower end of the sweep, while the 
remainder of the brick work is being built up and the loam swept on 
to it. When the core has been built to the required height, it is left 
in the position in which it was swept and the plate with the seat and 
core placed in an oven and dried. 

A vertical section of the completed mold is shown in Fig. 7. In 
order to arrange the parts as shown, the foundation plate with the 
seat and core upon it is taken from the oven and carefully leveled up 



4-III 



SWEEP WORK 



in the casting pit. The cast iron ring, with the outer portion of the 
mold, is next lowered in place. The circular covering cores for the 
nozzles are then placed in position and the central nozzle cores intro- 
duced through them as shown. 



WALL BRACE 




PARTING 
IN MOLD^ 



Fig. 4. Sweeping the Body of the Cylinder 




Fig. 5. Nozzle Pattern 



After the nozzle cores have been set, the space between the brick 
work and the mold is rammed up with sand to form a backing for the 
mold. 



A PLAIN CYLINDER 



5-III 



Slab cores are used to cover the top of the mold and suitable gates 
are cut through these slab cores and a pouring basin formed. Of 
course it is necessary to use weights for holding down the slab cores 
and the different parts of the mold. 

In the case of deep molds in which the iron would have to fall 
several feet from the gates, there is danger of cutting the mold by the 
first iron introduced and in such cases auxiliary gates are frequently 
formed by making a suitable gate into the lower flange and then ram- 




Fig. 6. Sweeping the Body Core 



ming up gate sticks in the sand backing, or by introducing a gate made 
in cores while ramming up the sand. 

The pouring basin is so arranged that the first iron will pass down 
through the bottom of this gate and into the bottom of the mold. 
After the bottom of the mold is thoroughly covered with molten iron, 
the ladle may be tipped faster and the metal introduced both from the 
bottom and from the top through suitable gates in the covering cores. 

For such a mold as this the patternmaker has to furnish the sweeps 
shown, together with the patterns and core boxes for the nozzles and 
in some cases the segment pattern for the foundation plate and the 



6-I1I 



SWEEP WORK 



lifting ring. He also has to furnish a core box for the slab covering 
cores. In such work as this, care should be taken to see that the 
nozzle patterns are so formed that there is a small amount of clearance 
between the edge of the sweep and these parts. 








•mM. 



m 

m 









Fig. 7. Section of Finished Mold 

As the lower parts of deep molds of this nature are apt to strain 
or swell, from the pressure of metal forcing the walls out and causing 
increased thickness of metal, it is often found practical to reduce the 
section of the lower part of the mold by setting the sweeps in a slightly 
inclined position. 



SUCTION CHAMBER MOLD 



7-III 



CHAPTER II 



SWEEPING THE MOLD FOR A SUCTION CHAMBER 



In the previous chapter there was described the sweeping of a 
comparatively simple mold in loam, together with the rigs necessary 
for the job. In this article will be described the molding of a suction 
chamber which differs from that shown in Chapter I on account of 
the fact that it is necessary to build up and sweep a temporary seat or 
cradle to assist in forming and drying the main core and also on 
account of the method employed for supporting and setting the core 
by means of a cope ring. This casting also serves to show how 
irregular partings can be made at any desired point in a mold. 




Fig. 8. Suction Chamber 

In preparing the rigging for a job of this kind, the patternmaker 
has to lay out a full sized radial section of the piece to be molded 
and then to make the necessary sweeps and part patterns, together 
with the core boxes for the latter. It is also necessary to make any 
strips, sweeps, or segmental patterns which may be required for mak- 
ing open sand molds for lifting plates, cope rings, etc. 

Ill the mold under discussion, which is shown in cross section 
in Fig. 14, it is necessary to provide some support for the cope. For 
this purpose a plate, similar to the one shown in Fig. 9, 'must be gotten 
out, but it is not necessary to have the projection at the right, the plate 
being circular with four bolting lugs. 

In carrying on the work it is first necessary to get out a founda- 
tion plate F, shown in Fig. 10, level it up and place the spindle S, 
taking care to see that it is plumb. The sweep A is then secured to 



8-III 



SWEEP WORK 



the spindle and the lower half of the nozzle pattern held in position 
by suitable supports as shown. The nozzle pattern must be set in such 
a position that the sweep just clears it. For setting this pattern the 
straight edge shown in the upper right hand corner of Fig. 10 will be 
found very handy. This is arranged with a notch A in the straight 




Fig. 9. Parting Plate 



Fig. 10. Setting of Sweep and Port Pattern 



edge cut to such a depth that when it is placed in contact with the 
spindle the straight edge is in line with the center of the spindle, — in 
other words, lies in a radial section. 




Fig. 11. Sweeping the Seat or Cradle 



The lower half of the nozzle pattern should be placed first and 
held in position by a weight, while the lower portion of the mold is 
being built. 



SUCTION CHAMBER MOLD 



9-III 



The circular portion of the mold below the cope ring G, Fig. 10, 
is built up of brick work covered with loam and swept ofif with the 
sweep A. When the brick work with its loam facing is complete to 
the joint, an offset parting is formed as shown at P, Fig. 10. 

The cast iron plate G, shown in detail in Fig. 9, is then placed 
upon this parting, the cope half of the nozzle pattern set in place, and 




Figr. 12. Building the Core 



the brick work and sweeping continued until the top of the mold is 
finished by sweeping it to the proper form for the flange and also 
sweeping the seat to receive the covering plate. 

The sweep and spindle are then removed and the portion of the 
mold above the parting lifted off. The pattern is then drawn, the 



lO-III SWEEP WORK 

opening at the bottom of the mold through which the spindle passed 
is patched up, and the opening left for the support of the nozzle pat- 
tern are also patched. The mold is then blacked and placed in the 
oven to dry. 

If this were a small casting it would be possible to sweep up the 
core in a reverse position and then roll it over, but in the case under 
consideration the casting is too large for this method and hence it will 
be necessary to sweep up a seat or cradle in which the lower portion 
of the core can be built. To do this a plate F, Fig. 11, is leveled up 
and the spindle A set perpendicularly and supported at the top. 




Fig. 13. Sweeping the Covering Plate 

The sweep B is then secured to the spindle, brick work built up. 
loam applied and swept off, so as to form the seat or cradle as shown 
in Fig. 11. Care must be taken to see that the interior of the seat 
conforms exactly with the desired interior surface of the casting. 

The cradle is then slightly dried, after which the core is built up 
in the manner shown in Fig. 12. 

First, a core plate or lifting plate L is placed in position at the 
lower portion of the mold. Loam is placed betw^een this and the sur- 
face of the cradle, and the space below, between and below the prickers 
which extend from the plate, is filled with molding sand which is 
thoroughly rammed and supported with rods or gaggers. Of course 
a loam facing is used next to the cradle after the space below the 
plate L has been thoroughly filled brick work is built upon it with 
a loam facing in contact with the cradle until the upper edge of the 
cradle is reached. 

The upper or parallel portion of the core is then built up and 
swept off with the sweep C, as in the case of any plain cylindrical 
piece. The outline of the upper portion of the core is shown by the 
dotted line. 

It is next necessary to make the covering plate, which serves both 
to cover the mold and to locate the core centrally. The manner of 
constructing this is shown in Fig. 13. The plate P is first leveled up 



SUCTION CHAMBER MOLD 



ll-III 



wrong side up and loam applied over the prickers and struck off with 
the sweep D. This plate is provided with holes H, through which 
bolts can be passed and secured to the lifting lugs H, in Fig. 12. After 
the loam has been swept on this plate and dried it is turned over upon 
the core shown in Fig. 12 and the two are bolted together as shown 
in the assembled mold in Fig. 14. Of course it is necessary to dry the 
core before applying the cover plate. 




Fig. 14. Section of Mold 



The various parts of the mold are now ready to assemble as shown 
in Fig. 14. First, the core for the nozzle is placed in position and sup- 
ported upon chaplets. Xext, the cast iron plate G carrying the upper 
portion of the outside of the mold is lowered upon the portion already 
in position, care being taken to place the necessary chaplets for holding 
down the nozzle core before the upper portion of the mold is lowered 
upon it. 

Next, the cast iron ring or cover plate, together with the core, are 
lifted from the cradle and lowered into position. At first they are 
lowered carefully while strips of clay are interposed at various points 
to test the metal thickness. The parts are then separated and if the 
metal thickness is correct, the parts are assembled and bolted together 
ready for casting. 

The cover plate is bolted down to the foundation plate as shown, 
and the space around the outside of the mold in the pit is firmly rammed 
with sand. The gating of the mold will vary according to the indi- 
vidual tastes of the molder in charge of the work. In many cases the 
gating is arranged either by ramming up gate sticks or by placing 
cores in the sand backing. 



12-III 



SWEEP WORK 
CHAPTER III 



SWEEPING CAST STEEL SLAG LADLE MOLDS 

When slag ladles are of cylindrical form, as shown in the two 
half elevations, Fig. 15, the mold is usually formed with sweeps, the 
striking edges of which contain radial sections of the interior and ex- 
terior forms of the ladle to be cast. The sweeps are attached to and 
revolve about a perpendicular spindle with the aid of sleeves and a 
collar. 




Fig. IS. Cast Steel Slag Ladle 

At the right in the illustration is shown the half elevation of the 
ladle containing one of the trunnions, while at the left is shown a half 
elevation at right angles to the other, so as to show one of the tipping 
lugs. 

The pattern work for such a job requires the laying out of a full 
sized radial section of the ladle, and the making of the sweeps and 
fitting them to the spindle, the making of the core prints for that 
portion of the trunnion core which extends into the cope, and the neces- 
sary core boxes for the trunnions and tipping lugs. 

When sweeping up molds for ladles of small diameter, say below 
four feet, as the one under consideration, a skeleton or built-up bottom 



A SLAG LADLE MOLD 



13-IIT 



as shown in position in Fig. 16, is usually made to form th;s portion of 
the mold. The use of such a partial pattern affords a surface for the 
molder to stand upon while using the sweep and finishing the mold. 




SPINDLE SOCKET 



Fig. 16. Sweep in Place 



After the completion of the preliminary pattern work, the molder 

takes the job in hand and begins operations by digging a hole in the 

floor to the depth of the ladle to be cast and firmly placing the spindle 

socket in position. 

The built up portion of the bottom of the ladle pattern is now 

placed in the bottom of hole and the spindle passed through the hole 



14-III 



SWEEP WORK 



in its center and seated in its socket as shown. The spindle is then 
plumbed and the wall or post braces adjusted. Next, the partial pat- 
tern is leveled up and firmly bedded in place. 

With the upper edge of the part pattern for a guide two surfaces 
are struck off diametrically opposite each other to receive the lug cores. 
These cores are prepared for insertion in the mold by stopping up the 
openings with waste or some other suitable material. 

During the sweeping of the inner surface, the lugs are set back 
from the first sweep a distance equal to the metal thickness by the 
aid of a strip bradded on to the side of the sweep. The lug cores are 



SECTION OC 
Fig. 17 





I^ 



a 




SECTION DO 

Fig. 19 

SECTION ££ 
Fig. 20 

Fig. 17. Core Print for Trunnion Fig. 19. Half Core Box for Tipping Lug 

Fig. 20. Half Core Box for Trunnion. 

shown in position in Fig. 16, together with the arrangement of the 
sweep during the two operations of sweeping. That is, the sweeping 
up of the inner form upon wdiich the core is rammed and the subse- 
quent sweeping off of the metal thickness. 

The sw'eep is attached to the spindle as shown and as the use of 
an ordinary solid sleeve causes more or less inconvenience in placing 
and removing sweeps, a split sleeve as shown in the upper left hand 
corner of Fig. 16 can be used to very good advantage. 

The sweep is constructed as shown in Fig. 16, being provided with 
a detachable strip A, equal in width to the required metal thickness of 
the ladle. A cross section of the sweep on the line U U with the at- 
tached strip A is shown in detail at the left of Fig. 16. 

After the completion of the bedding in of the ]:)art pattern and the 
Jocation of the two lug cores, the sweep without the strip .\ is attached 



A SLAG LADLE MOLD 



15-III 



and the inner form of the ladle swept up, a parting being made for 
the cope as shown at the right of the spindle in Fig. 16. The sweep 
and the spindle are then removed and the opening in the part pattern 
through which the spindle passes stopped up with waste to prevent 
the sand ramming into it. 

/RUNNER 

•RISER 














SM'A 



JION 
rOREBEDDED IN 




vMw^-'^' 



mm 



m£mm 




ill 

Jlfr^ — CAST IRON GRATE 



¥ 



Fig-. 18. Section of Mold 

With the aid of a straight edge and plumb bob the center line of 
the trunnions is scribed across the parting of the mold at right angles 
to the center line of the tipping lugs and the two core prints are placed 
in position. 

One of these core prints is shown in greater detail in Fig. 17. 
These prints are set diametrically opposite each other and on a line at 
right angles to the center line passing through the tipping lugs. 

Parting sand is next applied to the parting of the mold and the 
interior cylindrical surface of the ladle covered with paper. A grate 



16-III SJVEEP WORK 

or crab iron conforming somewhat to the form of the bottom of the 
core is next placed in position and provided with bolts of such a length 
that they will extend up through the cope. This crab iron is shown 
in Fig. 18. When ramming up the core a thickness of silica sand is 
placed around the outer surface. Ordinary heap sand is used back of 
this and the interior of the core filled with coke. 

When the ramming of the core, with its filling of coke, has reached 
the height of the parting line, the cope is placed on and staked in 
position. The core is now securely bolted to the cope. After the cope 
has been rammed, the cope, with the attached core, is lifted off, blocked 
up and finished. The outline of the two trunnion core prints is marked 
upon the parting by scribing a line around them, after which our 
attention is turned to the obtaining of the proper metal thickness. 
The swept surface of the interior of the mold is first roughed off with 
a shovel to a depth equal to the metal thickness of the ladje plus the 
thickness of silica facing to be used. The strip A is next attached to 
the sweep and the spindle returned to its proper position. The outer 
portion of the mold is then swept up with its silica facing, thus giving 
the required thickness of metal for the ladle. The depth of the trunnion 
cores is laid off on the sweep and transferred to the surface, after 
which the sweep and spindle are removed. 

Guided by the outline of the core prints scribed on the parting and 
the lines scribed on from the sweep, an opening is cut out on each 
side of the mold and the trunnion cores bedded in in the proper position, 
as shown at the right in the view of the cross section of the completed 
mold in Fig. 18. At the left of Fig. 18 is shown a view of the cross 
section of the completed mold through a tipping lug, together with 
the arrangement of gates and runners required. 

After the setting of the trunnion cores has been completed the in- 
side of the mold is dressed and the part pattern removed. The spindle 
hole is then filled up and the bottom portion of the mold slicked up and 
finished. This, as will readily be seen, is a rather awkward operation. 

The mold is then given a silica wash and dried. The cope is sub- 
sequently placed on and tried for metal thickness and if found correct, 
is securely weighted down, when the mold awaits the metal. 

The core boxes for forming one-half of the lug and trunnion cores 
are shown in Figs. 19 and 20. Two half boxes are required for each 
core. 



MOLDING A FURNACE BELL 17-III 

CHAPTER IV 

A FURNACE HOPPER AND BELL 

A cross section of a blast furnace hopper and bell of familiar 
design is shown in Fig. 21. These castings are frequently made from 
steel, and vary in diameter from 6 to 12 feet. When exceeding these 
proportions, they are usually cast in sections which are bolted together. 

While the sweeping or forming of molds of this description is com- 
paratively simple, it may embrace some points of interest. The method 
frequently adopted is shown in the accompanying illustrations and will 
serve to familiarize the patternmaker with this character of work, in- 
cluding the laying out and making of the accompanying sweeps, etc. 




Fig-. 21. Section of Bell and Hopper 

The bell being of conical form can be cast in either position, but 
is usually cast with the apex down, as this insures a better casting and 
allows risers to be placed upon the rim. This position also permits 
the inside to be lifted out with the aid of a skeleton or lifting plate. 

Molding- the Bell 

In beginning the work, a hole is dug in the floor equal in depth 
to the height of the bell and the spindle is set and plumbed as shown 
in Fig. 22, wall braces being used to secure the upper end and to hold 
the spindle rigidly. 

Shown in Fig. 23 is a partial pattern containing the apex of the 
bell and to which is secured the core print with the lifting lugs or ears 
attached. This part pattern is provided with a hole through the center 
to receive the spindle and to locate it in the proper position. It is 
firmly bedded in, forming the lower portion jf the mold, as shown in 
Fig. 22. 



18-1 I I 



SWEEP WORK 



Attention is also called to the manner of supporting the lower 
end of the spindle upon a center, as shown in I'^ig. 22. The advantage 
of this method is that any dirt which may be dropped into the hole will 
not interfere with the spindle. 

The sweep is constructed as shown in Fig. 22 and provided with 
a detachable strip D, equal in width to the required metal thickness 
of the bell. A cross section of the sweep on the line C-C, with the 



Wan Brace 



'l^^^rj!f^^:>K 




SECTION C-C 



Fis. 22. Spindle Set for Sweeping the Stopper 

attached strip D, is shown in greater detail to the right in Fig. 22. 
The sweep is attached to the spindle as shown. The split sleeve shown 
in Mg. 16 may be used in this case. This allows the sweep to be at- 
tached without disturbing the spindle, the sleeve being provided with 
a clamp secured with a bolt. 

There are two methods whicli may be used for sweeping up pieces 
of this description. Mrst, sweeping up of the inner surface or form 
of the required object, and then the sweeping off of the metal thick- 
ness after the central portion or core has been made. Second, the 



MOLDING A FURNACE BELL 



19- III 



sweeping up of the outer surface or form of the object, applying of 
parting sand, and then with the strip D removed, the sweeping on of a 
thickness of sand equal to the thickness of the metal, after which the 
core is rammed up on this surface. The thickness of sand forming 
the metal thickness is removed during the finishing of the mold. 

The method discussed in this article will be the first mentioned 
process, which is the one usually adopted in steel foundries. At the 
completion of the bedding in of the part pattern, the sweep without 
strip D is attached and the inner surface or form of the mold is swept 
up and the parting for the cope made, as shown in Fig. 22. 



-Hole for Spindle, 

■ Core Print___y^jYvHl-TlX '' 

Fig. 23 




Fig. 23. Pattern for Ape.x of B 



Fig. 26 

Fig. 26. Core Bo.\ for the Ears or Lugs 



The spindle sweeps, etc., are then removed, and the hole for the 
spindle in the part pattern stopped up. Parting sand is freely applied, 
and the skeleton shown in Fig. 24, with rods upon it to conform some- 
what to the shape of the mold, is placed in position and the ramming of 
the core begun. 

At the completion of the ramming of the core, the cope or flask is 
placed on and firmly rammed up, being securely bolted together some- 
what after the manner shown in the cross section of the complete mold, 
Fig. 25. 

The cope with the core attached is now lifted off, blocked uo, 
finished and dried. The inner surface of the mold is then roughed 
out, the spindle and sweep replaced, and with the strip D attached, the 
outer surface or form swept up, giving the required metal thickness. 
The spindle and sweep are then removed, the part pattern drawn, the 
mold finished, and the core forming the inside of the lugs, or ears, 
placed in position. The gate is arranged and the mold is dried. 



20-111 



SWEEP WORK 



The cope is now placed on, and if the metal thickness is found 
correct, the whole is weighted or bolted down, and prepared for casting. 

Two views of the core box used for forming the ears or lugs are 
shown in Fig. 26. 

Molding the Hopper 

In tiiis particular case, the molding of the hopper differs from 
that of the bell, inasmuch as only the outer surface is formed with a 



IT' 




r'fi^-i r ^- r^ 



_.4i__,___j_-t^ 



P'^. 

^^m^^ 



^Ss 



.^^' 



^. 




Skpletoii 



w 



^ 



V 



Fig- 24. Skeleton for Core 






Fisr. 25. Section of Mold 



sweep, the inner surface being obtained with the aid of lagging and 
strips in thickness equivalent to the metal thickness of the hopper. 
These lagging pieces being used as shown, the strips are placed at in- 
tervals around the mold, forming a guide by which the required depth 
can be struck off from the core, to give the proper metal thickness. 

A cross section through the center of the mold for the hopper is 
shown in Mg. 27. To the right of the spindle is shown the construc- 
tion and arrangement of the sweep, as it appears during the operation 
of sweeping the outer surface or form of the mold with the flange and 
parting at the top, also the seat for locating the core. 



MOLDING A FURNACE HOPPER 



21-III 



At the left of the illustration, the form of the mold after sweeping 
is completed, is shown, with the lagging and strips for giving the metal 
thickness, in place. 

The outline and position of the covering core is also shown in 
dotted lines. 

The operation of sweeping being complete the spindle and sweep 
are removed and parting sand or paper applied to the swept surface. 
Paper is generally applied to the walls of the mold. 




Fig. 27. Section of Hopper Mold with Sweep in Place 



The undersweep surface G is now filled in with lagging, so as to 
close off this depression, and the metal thickness strips are placed in 
position. A core bar, consisting of a series of round flasks of con- 
venient diameter and depth, which have been firmly clamped and 
bolted together, and provided with wing bars bolted to their outer 
diameter, is now lowered into the mold and centrally located upon the 
seat. Sand is firmly rammed and rodded into the inclosure formed 
by the outer diameter of the flasks and the swept surface of the mold, 
the top being furnished with a seat or surface to receive the covering 
core. This is accomplished with the aid of a segment conforming to 
the swept core seat and flange and applied in the manner shown in 
Fi^. 29. 



22 III 



SWEEP IVCRK 



The core bar, made up of flasks, is now lifted out with the sand 
core intact and blocked up. The thickness strips are removed and with 
these depressions acting as guides for the depth, the metal thickness 
is struck ofif and the core finished and dried. 



Segment 




FI9. 30 



Fig. 31 

Fig. 28. Segment to Form Seat for Covering Core Fig. 30. Core Box for Covering Cores 

Fig. 31. Use of Cores to Form Inside of Mold 



Covering Core 




Fig. 29. Completed Mold 

The lagging in the portion of the mold G, Fig. 27, being removed 
the mold is treated in the usual manner. The parts are then assembled, 
as shown in the cross section of the complete mold, Fig. 29, the cover- 
ing cores being formed in the box shown in Fig. 30. 

These are used to form the upper surface of the flange and close 



MOLDING A FURNACE HOPPER 23-III 

the top of mold, openings being filed in a number of these covering 
cores at different points around the mold, at which points risers are 
built up. 

The runner is arranged through the center of the mold or flasks, 
and the castings gated from below. The whole structure is then 
weighted down and prepared for casting. 

Another method practiced in some cases is illustrated in Fig. 31. 
In this case, cores are used to form the inner surface of the mold and 
the upper face of the flange. The inner surface or form of the mold 
with the seat for the cores at the top and bottom is swept and dried in 
the manner already described, after which the series of cores are placed 
around the inside of the mold, §o as to form the metal thickness, pro- 
vision of course being made for the runner and gating, after which 
sand is firmly rammed within the inclosure formed by the cores form- 
ing a solid core. 



24-III 



SWEEP WORK 
CHAPTER V 



SWEEPING A CYLINDRICAL AND CONICAL DRUM 

The accompanying illustrations show a combined cylindrical and 
conical hoisting drum with a variable pitch score, and also one method 
of sweeping the same in loam. These drums, two in number, form a 
right and left when placed together, and were designed by the Well- 
man-Seaver-Morgan Co. They were used in the construction of an 
electric automatic water hoist, in an anthracite coal mine near Scran- 
ton, Pa. 




Fig. 32 Cylindrical and Conical Drum. 

This design of hoisting drum is employed in winding heavy loads 
from deep mines. When the skip or load is at the bottom of the mine, 
ready to be hauled up, the winding of the cable begins at the small 
cylindrical end. This prevents the load from starting too suddenly, 
and allows the slack cable in the shaft to be gradually taken up at the 
beginning of the hoist. The motor or engine also gains a decided 
advantage when these drums are employed, as the winding starts at a 
slow speed and gradually increases, thus giving the motive power a 
better chance to do its work, and reducing the strain to a minimum. 

Fig. 32 gives a cross section of the drum ; to the right is shown 
the metal thickness, and to the left the bolting flange with its splitting 



A CYLINDRICAL AND CONICAL DRUM 



25-III 



margin along the joint and around the bolt holes. The drum is cast 
practically entire, and subsequently split in two. 

It will be seen that the drum is 16 feet in diameter at the large 
end, and 10 feet at the small end. The conical section is very flat, 




Fig. 33. Plan of Drum 

and increases from the small to the large diameter in four revolutions. 
Fig. 2)2) gives plan of drum at the small cylindrical end, showing ribs, 
bolting flanges, etc. 

As the rig or device employed in producing conical drums of this 
description is one of the principal features, upon which the accuracy 




Fig. 34. Spindle Screw 

of the work greatly depends, its calculation and construction usually 
receive the initial attention, therefore we shall proceed in this wise. 

Special Sweeping Rig 

The variation in the axial pitch of the drum score was produced 
by a variable pitch thread cut upon the cast iron hollow spindle, as 
illustrated in Fig. 34. This thread receives the conical roller A, which 
is provided with a roller bearing bracket B, as shown in plan and 



26-1 II 



SWEEP WORK 



section, Fig. 35. The outer diameter of the spindle is turned to the 
required dimension, six inches, the variable pitch thread is laid off, 
and holes drilled at the ])oints where the pitch of thread changes. The 
spindle is then returned to the lathe, and the required pitch of thread 
between the drilled holes cut, the spindle being finished at the top and 
bottom as shown. 




Fig. 35. Roller Bearing Bracket Fig. 36. Sweeping Rig 

Three views of the assembled device are shown in Fig. 36, giving 
the general construction of the frame. The material used is hard 
wood. The sliding arm C is held in place as shown, and with the 
aid of rollers D, is allowed to travel or slide freely. Gear E at the 



A CYLINDRICAL AND CONICAL DRUM 



27-111 



top of the frame is attached to the spindle with a feather key, per- 
mitting it to travel up and down the spindle as the frame is raised or 
lowered. As the frame is revolved around the spindle, gear E drives 
gear F, which, by means of shaft G, pinion H, and rack I, causes the 
sliding arm C to travel radially backward or forward, as the case 
requires. 

The raising or lowering of the frame is governed by the engage- 
ment of the conical roller A, with the thread of the spindle. The 
bracket B is located and secured to the lower part of the frame at J. 
The proportion of gears governing the travel of arm C during the 
sweeping of the conical section of drum is as follows: The angle of 
the conical section is 120 degrees, giving a 9-inch throw to the 5-inch 
pitch ; that is, the frame would rise 5 inches in one revolution, while the 
arm C would travel outward 9 inches. The gears are of ^ circular 
pitch, gears E and F having a pitch diameter of 10.15 inches, and 64 
teeth; gear H contains 18 teeth with a pitch diameter of 2.86 inches. 




Fig. 37. Foundation Plate and Spindle Setting 



These proportions give the gears the same number of revolutions as 
the frame. 

When using the frame with the arm C stationary, as in the sweep- 
ing of the cylindrical sections, gear E is thrown out of mesh with gear 
F by being raised up and a block or support placed underneath it. 
This also requires the disengaging of the roller from the thread of the 
spindle. The frame is now held suspended and revolved upon the 
collar K ; the collar being dropped down upon the spindle socket when 
not in use. 

Sweeping the Mold 

The pit having been dug to the depth of the drum, a bed is struck 
off for foundation plate A, which is placed in position and leveled up 
with the spindle socket attached, as illustrated in Fig. 2)7. The socket 
is bushed as shown, to receive an ordinary spindle, to which is attached 
the sweep C. The brick work is now built up to the required height in 
the usual manner, and a heavy facing of loam applied and struck off 



28-1 I I 



SWEEP WORK 



to the form of the sweep. The cutting edge of tlie swee]) forms the 
seat for the core, and also a surface and guide for ])lacing flange D, 
which is shown in position to the left. 

Fig. 38 illustrates the rig in operation, showing the arm with the 
various cutters and strikes attached, which are employed at the different 




stages of sweeping the mold. To the right are shown the cutters G, 
H and I, required in forming the score. They are made of ^-inch. 
steel plate, dressed to form and the back beveled off, forming a com- 
paratively sharp edge. To the left are shown the strikes J and Z, 
employed in sweeping on a body of sand the equivalent of the metal 
thickness. 



30-III 



SWEEP WORK 



With the seat for core prepared and flange D in position, the 
scoring of the mold is in order. Following the plumbing of the spindle, 
the frame is lowered down over it, and the upper end secured with 
guy rods attached to flange L. With the roller engaged with the 
thread of the spindle, the gear E thrown out of mesh with gear F, the 
frame is placed in position at the starting point, this being governed 
by the thread of the spindle. The slide with cutter G attached is next 
adjusted to the required diameter of score, and the slide locked in 
position, as shown to the right at the starting point. 

The brick work with a heavy loam facing, which is struck off to 
the form of cutter along its helical path, is now laid until the conical 
section is reached. Cutter H is now attached to the slide as shown, 
gear E dropped into mesh with gear F, causing the slide to travel out- 
ward as the frame is revolved. 

rRif 




Fig. 42 

Fig. 41. Grates for Holding the Core 



Fig. 41 



Fig. 42. Sweeping of Coven'ng Ring 



As the changing of these cutters and pitch of scoring is rather 
abrupt, a little doctoring or making up of score becomes necessary at 
this point, and is accomplished with the aid of a segment representing 
a section of scoring. The segment is so dressed that it works from 
one section to the other. This mending up also becomes necessary 
when the large conical and cylindrical sections meet, at which time 
cutter I is attached, and the bricking and scoring completed to the top. 

At the top a surface to receive the covering ring is struck off with 
the aid of strike AI, attached to the slide, as shown to the left. This 
necessitates the throwing out of the gears and conical roller, the frame 
being supported and revolved upon the collar K. 

With this porti(in of the mold completed and air-dried, a body of 
ordinary sand, equivalent to the metal thickness, is then swept on. The 
gears and conical roller having been disengaged, the strike Z attached, 
and the slide locked to the inside diameter, the frame is lowered until 
the strike clears the flange D, and the collar K adjusted. This thick- 
ness of sand is now swept up on the small cylindrical section of the 
mold, as shown. 



A CYLINDRICAL AND CONICAL DRUM 



31-111 



The conical section being reached, the strike T is attached, the 
conical roller engaged with the thread of the spindle, and the gears 
dropped into mesh and this thickness of sand swept up on the conical 
section. The large cylindrical section is treated like the small section, 
strike Z being employed. 




The frame and spindle are now removed, paper applied to the seat 
for the core, a heavy loam facing spread over it, and the lifting plate N, 
upon which the core is built, as shown in cross section of mold, Fig. 
39, pressed down upon it ; to which it adheres, forming a seat and guide 
for locating the core when returned to the mold. The ribs and bolting 



32-111 



SWEEP WORK 



flanges, Fig. 40, with splitting and bolt core prints attached, are now 
placed in position. They support the flange E, as shown in Fig. 40. 
This flange and flange D are in sections, which allows their being 
drawn in or back, as the case requires. The arrangement of ribs, etc.. 




is screwed together, the screws being removed as the building of the 
core progresses. 

Building the Core 

The bricking, strengthened with rods and plates, having a thick- 
ness of loam between it and the molding sand thickness, which repre- 
sents the metal thickness of the drum, is now placed upon the lifting 



A CYLINDRICAL AND CONICAL DRUM 33-III 

plate N, Fig. 39, until the conical section is reached. Open sand grates, 
as shown in Fig. 41, are now employed to secure the overhanging brick 
and loam, the grates increasing in length as the building of the core 
progresses. The small end is kept somewhat in line, allowing the 
sixteen clamping bolts to pass up through them. The height of the 
conical section is built up in this manner ; plate P, Fig. 39, is placed 
upon the grating with its filling of brick and loam, and this portion of 
the core securely clamped together. Brick and loam are now applied 
to the top of the plate, and the remaining portion of the core com- 
pleted and the top finished, as shown. 

A center line for the splitting core is now laid off across the top 
of the core and outer wall of the mold. 

The lifting plate is provided with four staples, as shown. The 
core is lifted from its seat with the aid of a four-way cross, as shown 
in Fig. 43, and placed upon a car, the ribs and flanges drawn, the core 
dressed and placed in the oven and dried. 

The lower flange is drawn and the sand forming the metal thick- 
ness is removed from the mold, it is then treated in the usual manner, 
and thoroughly dried by the aid of coke fires placed in it. 

Owing to the deep scoring of the conical section of the drum, the 
splitting of the projecting metal between the score is an object to be 
considered. This can be overcome to a nicety with ^-inch steel rods 
in the following manner : By the aid of a plumb-bob and straight-edge 
across the top of the mold, the center line of the drum at the splitting 
core is projected down the side of the mold, and ^-inch machine steel 
rods driven in opposite these projections, as shown to the right in 
Fig. 39. This same figure also shows the splitting and bolt cores in 
position. The bolt cores are placed through the splitting core, but 
independent of it, being secured by the tail prints, leaving a j/2-inch 
metal thickness around the bolt holes. 

The splitting core consists of a perforated ^-inch cast iron plate, 
covered with loam, forming a core of about ^^-inch in thickness. To 
facilitate the handling and setting of these cores, and to lessen the 
danger of the cast iron plate warping or expanding when heated from 
the metal, thus causing the loam to crack and chip from the plate, the 
cores are made in three sections. A complete core box is used, the cores 
being separated by the introduction of pieces of tin at the desired 
lengths. The splitting preparations being completed, the mold is ready 
to be assembled. 

The core is lowered into place, and the cope ring placed on. This 
ring consists of a cast iron prickered semi-ring, or plate, provided with 
lifting lugs and openings for gating. To the prickered surface a heavy 



34-III 



SWEEP WORK 



facing of loam is applied, and struck off with the aid of a spindle and 
sweep, as shown in Fig. 42. 

The clamping of the mold is accomplished with the assistance of a 
six-way cross in a very positive manner. Foundation plate A is pro- 
vided with lugs corresponding with the arms of the cross, and the tie 
rods are attached to it, as shown. The crane is now hooked on to the 
cross, and given a heavy lift, and while being subjected to this strain, 
the blocking between the covering ring and cross is placed in position 
and securely wedged up. 

The intervening space between the wall of the mold and the side 
of the pit is firmly rammed in with sand. The runners, two in num- 
ber, are located opposite each other, and are prepared during this ram- 
ming or backing up. 




Fig. 45. Finished Casting 

The gating to the lower flange is not on a radial line, as shown to 
the left, Fig. 39 (this being simply for illustration), but is carried 
farther around the flange so as to cause the metal to whirl or circulate 
as it rises in' the mold; this provision being necessary to offset the ten- 
dency of the metal to become sluggish or chilled as it nears the top. 

The pouring of the mold does not depend entirely upon the gating 
from below, as the mold is provided with a series of pop gates closed 
with cast iron stoppers and connected with the pouring basin, as shown 
in Fig. 39. During the pouring, and when the metal has reached the 
top of the conical section, the ladles are tipped, choking the runners, 
and causing the metal to back up over the pop gates to the depth of 



A CYLINDRICAL AND CONICAL DRUM 35-111 

three or four inches. The stoppers are now Hfted out, causing the 
metal to drop into the mold. 

A photograph of the mold during the operation of sweeping is 
shown in Fig. 44. 

A view of the mold with the core suspended from one crane im- 
mediately behind it and the six-way cross for tying down the cope sus- 
pended from the other crane near it, is shown in Fig. 43. The finished 
casting is shown in Fig. 45. 



36-ni SWEEP WORK 

CHAPTER VI 

SWEEPING RIGS 

A Double Sweeping Frame 

The accompanying illustrations show a convenient sweeping rig, 
to which may be attached various strike boards, the striking edge of 
which contain radial sections of the pieces to be swept up. As the 
strike boards are rigidly and permanentl}' secured together with cleats 




Fig. 46. Section of Dome Casting 

they can be attached to or removed from the rig very quickly as the 
case may require, no special adjusting being necessary. The advan- 
tages of the rig can readily be seen, for if a casting is to be duplicated 
all that is necessary is to go to the pattern storage, get the strike boards, 
and attach them to the .Ig. 

The blocks B-B, Fig. 47, upon the cleats which secure the boards 
together guide the parts into their correct position upon the rig. 

The rig is shown as applied to the sweeping up of a green sand 
mold for producing a dome casting, as shown in half section and half 
elevation in Fig. 46. 

The assembled arrangement of the rig with the strike boards at- 
tached is shown in Fig. 47. At the right of the spindle the operation 
of sweeping the exterior form of the dome is shown in progress. Upon 
this sweep surface the cope is subsequently rammed up. At the left 
of the spindle the rig is shown in the reverse position or upside down, 
as wnen set for sweeping off the metal thickness or striking up the 
interior form of the dome. Of course, the striking up of the interior 
form takes place after the ramming up and lifting off of the cope. 

The separate parts of the arrangement are shown in Fig. 48. The 
rig itself is shown at the left, and consists of a rigid frame made from 
33^ X 1^-inch material, the frame being strengthened by cross braces, 
as shown. The spindle sleeves are of the hinge design, as this form 
of sleeve allows the rig to be attached to or detached from the spindle 
without disturbing the latter ; that is, the spindle can be set up and 



A DOUBLE SWEEPING RIG 



87-III 



adjusted and the rig attached afterward. The sleeve is shown in 
greater detail above the frame. 

At the right of Fig. 48 are shown the strike boards as they would 
appear when removed from the rig. Care should be taken in attach- 
ing boards together to see that they are rigidly secured to the cleats 
with screws and a spot of glue at the extreme ends of the cleats. There 
are two advantages in this manner of gluing. First, any shrinking or 




Fig. 47, Assembled Rig 



swelling that may take place in the boards will be toward or from the 
glue spots at the ends of the cleats and will prevent the striking edge 
of the boards being distorted. Second, if glue was applied to the por- 
tion of the cleats extending across the boards, warping of the boards 
would be the result. In fitting the boards to the frame the latter is laid 
down and the boards with the striking edge dressed to form, placed in 
about their correct position and the cleats attached. 

Next the centering pin shown directly above the striking boards 
in Fig. 48 is used in locating the blocks B-B, Figs. 47 and 48. 

These blocks should be securely fastened in place with glue and 
screws. The centering pin is usually turned up from well-seasoned 
hardwood, its diameter being the same as that of the spindle. A por- 
tion of the center is cut out to half the diameter and the center line of 
the pin scribed thereon. By shoving the pin through the sleeves as if 



38-III 



SWEEP WORK 



it were the spindle and turning the flcit side of the pin into the plane 
of the striking boards, the center line upon the pin becomes immediately 
' available for setting the boards. 




i 



X 
Centering Pin I 



•ing Pin I JCenter Li 

^=^ I / ^ 




Fig. 49 




Fig. 48 



—A 



Fig. 48. Details of Sweeping Rig 



Fig. 49, Eccentric Collar 



An Eccentric Spindle Collar 

The accompanying illustrations show an eccentric collar applied to 
an ordinary foundry spindle for sweeping up circular molds. This is. 
especially adapted to the sweeping up of circular work that is cast in 



AN ECCENTRIC SPINDLE COLLAR 



39-1 I I 



halves, the mold being divided or separated by what are termed split- 
ting cores. 

To split such work usually necessitates the shifting of the spindle 
a distance equal to the thickness of the splitting core used. This is 
often an awkward operation owing to the fact that the adjustment must 
be made below the floor level. 




Fig. 50. Eccentric Collar Rig in Use 

The collar under description avoids such trouble very nicely, the 
piece is bored out and turned up as shown in Fig. 49 with any desired 
throw. The center line AA should be scribed distinctly across the face 
of the collar. 

This device is especially adapted for the molding of sections of 
gears, etc., where a section of the rim or a segment is used in ramming 
the outside diameter as shown in Fig. 50. To adjust the collar to the 
arm of the rim or segment a hole is cut at the exact center of the work, 
the diameter of the hole being sufficient to receive the portion of the 
collar marked B, Fig. 49. 

The spindle is first set and plumbed in the usual manner. The 
collar is then slipped over it and secured by the set screw C at about 
the right height from the bottom. The arm with the segment attached 



40-III SWEEP WORK 

is now let down over the spindle and centered upon the collar which 
holds it in the proper position and allows it to revolve upon the 
shoulder D. 

As is the general practice, the segment is first set around the en- 
tire circumference, using flour to mark the correct position and spacing. 
When the spacing is found to be correct, a straight edge is placed across 
the center of the mold, as indicated by the dotted lines in Fig. 50. At 
the center the straight edge is cut out to receive one-half of the collar 
at the diameter B as shown. This brings the front edge of the straight 
edge in line with the center of the gear and locates the stopping point 
in ramming up this half of the wheel. Care should be taken in laying 
off this center line to see that it is parallel with the center line A\ of 
the collar. 

After one half of the mold has been rammed up the center line AA 
is marked on the spindle and the collar given a half revolution. The 
other half of the mold is rammed up just like the first half, care being 
taken to see that the space allowed for the spacing cores is equal on 
the two sides of the mold. 



SECTION IV 

GEARING 

CHAPTER I 
SPUR GEARING 

The theoretically perfect gear wheel is a friction wheel communi- 
cating a smooth, uniform rolling motion by means of frictional con- 
tact of its surface. It is, in fact, a gear wheel with a great many very 
small weak and irregular teeth. Such a gear as this is manifestly 
imperfect, subject to slip, and on the whole not suitable for many 
purposes. The whole object of the science of gear wheels is to increase 
the size and strength of the teeth without destroying the uniformity of 
the motion transmitted. This is accomplished by so forming the out- 
lines of the teeth that they will produce the desired result. Theoreti- 
cally, there are an infinite number of curves that will meet the require- 
ments, but only two are of any practical importance or have come into 
use to any extent. These are the epicycloidal and the involute. 

Definitions 

The spur gear is one whose teeth are parallel to its axis. It is 
used for transmitting motion from one shaft to another whose axes 
are parallel. There is also a class of spur gears called herring bone 
gears or double helical spur gears in which, while the axes are paral- 
lel, the teeth are arranged spirally around the cylindrical surfaces of 
the gears. 

Bevel gears are gears used to transmit motion between shafts at 
right angles to each other, the shafts being in the same plane. The 
teeth of the gears must necessarily stand at an angle to the axis. 

Miter gears are bevel gears whose teeth stand at an angle of 45 
■degrees to the axis and are used to transmit motion between shafts 
at right angles, in which the number of revolutions of the two shafts 
is the same. 



2-1 V GEARING 

Angle gears are similar to bevel gears, except that while the shafts 
intersect they are placed at some other angle to each other than 90 
degrees. This angle may be either obtuse or acute. 

A IiKiitiiig tooth gear is a gear into which an extra tooth has beeu 
introduced so as to make the number of teeth in the gear and pinion 
prime to each other so that any two teeth will not come in contact 
until each tooth in the small gear has been in contact with every tooth 
in the large gear. This tends to equalize wear on the gears. A hunt- 
ing tooth may be introduced either into bevel or spur gears. 

An internal gear is a spur gear having teeth on the inside of its 
periphery in place of on the outside and the pinion or smaller gear is 
situated inside of the large gear. In an internal gear the shapes of 
the teeth correspond to the spaces in an ordinary spur gear of the 
same pitch and diameter, with the exception of the fact that the back- 
lash and clearance are reversed in position. 

A rack is a straight bar having gear teeth formed upon it. It may 
be considered as a gear of infinite radius. 

When two gears act upon each other, the greater is termed the 
gear and the less the pinion. 

The word diameter when applied to gears is always understood 
to mean the pitch diameter. The tooth curves are always developed 
from the circle which represents the pitch diameter. 

Circular pitch is the distance between corresponding points of 
adjacent teeth measured along the pitch circle and is obtained by 
dividing the length of the circumference of the pitch circle by the 
number of teeth in the gear. 

Diametral pitch is the number of teeth in a gear divided by the 
number of inches in the diameter of the pitch circle. In other words, 
it is the number of teeth per inch of the pitch diameter of the gear. 

The thickness of a gear tooth is its thickness measured on a pitch 
circle. 

The space between two gear teeth is the space measured on the 
pitch circle. 

The addendum is that part of the tooth outside the pitch circle. 

The dedendum, or root, is that part of the tooth inside the pitch 
circle. 

The hack-lash is the side clearance between the two teeth in mesh. 

The clearance is space between the point of a tooth and the bot- 
tom of the space into which the tooth meshes. 

The face of a tooth is the working surface from the pitch circle 
to the point of the tooth. 



SPUR GEARS 3-1 V 

The flank of a tooth is the surface from the pitch circle to the 
root of the tooth. 

The length of a tooth is the distance from the root of the tooth 
to its point. 

The pitch point of a tooth curve is the point in which the outHne 
of a tooth intersects the pitch circle. 

When two gears are so located that their teeth run together, the 
gears are said to be in mesh. 

Rules 

When the circular pitch is given to obtain the diametral pitch, 
divide 3.1416 by the circular pitch. 

When the diametral pitch is given to obtain the circular pitch, 
■divide 3.1416 by the diametral pitch. 

When the number of teeth and the circular pitch are given to 
obtain the pitch diameter, multiply the circular pitch by the number 
cf teeth and divide the product by 3.1416. 

When the number of teeth and the diametral pitch are given to 
obtain the pitch diameter, divide the number of teeth by the diametral 
pitch. 

When the pitch diameter and the circular pitch are given to 
obtain the circular pitch, multiply the pitch diameter by 3.1416 and 
divide by the circular pitch. 

When the pitch diameter and the diametral pitch are given to 
obtain the number of teeth, multiply the pitch diameter by the dia- 
metral pitch. 

When the pitch diameter and the number of teeth are given to 
obtain the circular pitch, multiply the pitch diameter by 3.1416 and 
divide by the number of teeth. 

When the pitch diameter and the number of teeth are given to 
obtain the diametral pitch, divide the number of teeth by the pitch 
diameter. 

Involute Teeth 

The involute curve is the curve which would be drawn by a 
pencil point at the end of a thin band that will not stretch and is 
drawn tight while being unwound from a cylinder. 

The base circle in the involute system of gearing is the circle 
from which the involute curve that forms the tooth outline is drawn. 
The base circle is always inside of the pitch circle. The base circle 
for the 15 degree involute tooth is inside the pitch circle a distance 
equal to 1-60 of the pitch diameter, and the base circle for the 20 



4-IV 



GEARING 



degree involute tooth is inside of the pitch circle by a distance equal 
to about 3-100 of the diameter of the pitch circle. 

Fig. 1 shows the manner of developing or drawing the 15 degree 
involute tooth curve. A is the pitch point of the pitch circle. The 
line B-C is drawn at an angle of 15 degrees to a tangent to the pitch 
circle at the pitch point. The base circle is then drawn tangent to 
the line B-C. 




Figr. 1. Development of 15° Involute Tooth \ 



\ 



The line B-C is called the line of action, as it is along this line 
that the gear teeth will be in contact. In laying off a gear tooth any 
convenient number of points may be stepped off between the pitch 
point A and the point of tangency of the base circle G. With the 
dividers set at the same distance succeeding points are stepped off along* 
the base circle as shown at L, K, J, I, H, G, F, E, D, and S. Point S 
is one point in the tooth curve. Tangents to the base circle should 
then be drawn at the points D, E, F, H, I, J, K, and L and on these 
tangents distances equal to the arcs which they correspond to should 
be stepped off. This will give a series of points M, N, O, P, Q, etc., 
which are points in the desired tooth outline. A smooth curve drawn 
through these points will represent the outline of the tooth. 

An approximate method of drawing a 20 degree involute curve 
js shown in Fig. 2. This method can, however, be applied to any 
ether degree of involute teeth equally well. The pitch circle should 
be drawn first and spaced off to correspond with the pitch points. 
One of the spaces should then be divided, giving the point O, which 



SPUR GEARS 



5-IV 



corresponds to the center of the tooth on the pitch circle. Through 
this point draw a radial line and at right angles to it a tangent as 
shown. From this tangent lay off an angle of 20 degrees and draw 
the line A-B. Tangent to the line A-B draw the base circle. Also 
draw the radial lines C, D and E through the pitch points of the 
teeth. At the pitch point on the line C draw a tangent to the pitch 
circle, lay off 20 degrees and draw the line F-G. In like manner from 
the pitch point on the line D draw a tangent, lay off 20 degrees and 
draw the line H-I and also from the pitch point on the line E draw 




Fig. 2. Approximate Method of Drawing 20' Involute Tooth 

a tangent, lay off 20 degrees and draw the line J-K. It will be noted 
that all of these lines pass through a pitch point on the pitch circle 
and hence are tangent to the base circle. The point L where the lines 
F-G and H-I intersect will give a center for the flank radius to use 
for drawing that portion of the tooth outline between the base circle 
and the root, and the point M where the lines H-I and J-K intersect 
will give the center for the face radius which is used in drawing the 
portion of the tooth curve outside the base circle. The points L and 
M will fall very close to the base circle, in fact, close enough so that 
for all the teeth the centers may be taken on the base circle. By this 
means, it will be noticed that, circular arcs of approximately the same 
form as the involute curve have been substituted for it. 

Drawing the Epicycloidal Curve 

An epicycloid is a curve formed by a point on the circumference 
of the circle as it is beine rolled on the outside of another circle, while 



6-IV 



GEARING 



a hypocycloid is a line generated by the point on the circumference 
of a circle that is being rolled on the inside of another circle. 

In the epicycloidal system of gearing the faces of the teeth are 
formed of epicycloids and the flanks by hypocycloids, as shown in 
Fio-. 3. The complete circles are not drawn in this case, but only short 
arcs, though the centers for the circles are shown on the radial lines. 

The circle rolled upon the other circle to generate the tooth 
curve is called the circle of action or the generating circle and is 
rolled upon the pitch circle. In laying off this tooth, the pitch circle, 
addendum circle and root circle should be drawn first. The pitch 
circle is then spaced off to correspond with the number of teeth desired. 




Fig. 3. Drawing Epicycloidal Teeth 

In order to lay off the tooth curves from the pitch point A step off 
equal divisions on the pitch circle right and left as shown. Through 
these points radial lines are drawn and from centers upon these radial 
lines arcs of the circle of action are drawn as shown. In order to 
determine the points of the tooth curves it is necessary to measure 
off on these arcs of the generating circle distances corresponding to 
the portion of the pitch circle which has been rolled over between the 
point A and the point where the radial line intersects the pitch circle. 
For instance, to find the point Z, step off the distance from A to K 
upon the pitch circle with a pair of dividers. Then step off cor- 
responding distances along the generating circle from K to Z, thus 
obtaining the point Z. The point Y is obtained by stepping off the 
distances from A to J and back along the generating circle to Y. 
X and W are obtained in like manner and the points V, U, T, S, and 



SPUR GEARS 



7-IV 



R of the flank curve are in like manner obtained by stepping off dis- 
tances from the pitch circle to radial lines at B, C, D, E, F, and G and 
then back along the generating circles to points V, U, T, S and R. 
After the points are obtained a smooth curve is drawn through them 
Avhich will represent the desired tooth curve. 

Involute Odontograph Table 

In practice these theoretical curves are rarely laid out, approxima- 
tions being used which are obtained by means of circular arcs. The 
radii for these circular arcs are commonly obtained from odontograph 



GRANT'S INVOLUTE ODONTOGRAPH 

STANDARD INTERCHANGEABLE TOOTH, CENTERS ON BASE WNE 





Divide by the Diametrical Pitch 


Multiply by the Circular Pitch 


Teeth 


F. 


G. 


F. 


G. 




Face Radius 


Flank Radius 


Face Radius 


Flank Radius 


• 10 


2.28 


.69 


.73 


.22 


11 


2.40 


.83 


.76 


.27 


12 


2.51 


.96 


.80 


.31 


13 


2.62 


1.09 


.83 


.34 


14 


2.72 


1.22 


.87 


.39 


15 


2.82 


1.34 


.90 


.43 


16 


2.92 


1.46 


.93 


.47 


17 


3.02 


1.58 


.96 


.50 


18 


3.12 


1.69 


.99 


.54 


19 


3.22 


1.79 


1.03 


.57 


20 


3 32 


1.89 


1.06 


.60 


21 


3.41 


198 


1.09 


.63 


22 


3 49 


2.06 


1 11 


.66 


23 


3. 57 


2.15 


1.13 


.69 


24 


3.64 


2.24 


1.16 


.71 


25 


3.71 


2.33 


1.18 


.74 


26 


3.78 


2.42 


1 20 


.77 


27 


3.85 


2.50 


1.23 


.80 


28 


3 92 


2.59 


1.25 


.82 


29 


3.99 


2 67 


1.27 


.85 


30 


4.06 


2.76 


1.29 


.88 


31 


4.13 


2.85 


1.31 


.91 


32 


4.20 


2.93 


1.34 


.93 


33 


4.27 


3.01 


1.36 


.96 


34 


4.33 


3.09 


1.38 


.99 


35 


4 39 


3.16 


1.39 


1.01 


36 


4.45 


3 23 


1.41 


1.03 


37—40 


4 20 


1.34 


41—45 


4.63 


1.48 


46-51 


5.06 


1.61 


52—60 


5.74 


1.83 


61—70 


6.52 


2.07 


71-90 


7.72 


2 46 


91—120 


9.78 


3.11 


121—180 


13.38 


4.26 


181—360 


21.62 


6.88 



Draw the rack tooth by the special method. 

— [From Grant's Treatise on Gear Wheels. 



8-IV 



GEARING 



tables. In Grant's work on Gearing, he gives an involute odonto- 
graph table from which radii for various sizes of gears can be obtained. 
Fig. 4 illustrates a method of laying out an involute tooth by means 
of this odontograph table. 




The pitch circle or pitch line should be drawn first and the adden- 
dum line drawn outside the pitch line at a distance from it equal to 
one divided by the diametral pitch or to 1-3 of the circular pitch. The 
dedendum line should be drawn inside the pitch circle the same dis- 
tance, but in practice this is not used, the root line being inside of the 
pitch line by a distance equal to 9-8 of the addendum. 



SPUR GEARS 



9-IV 



The base line is drawn inside the pitch Hne by a distance of 1-60 
of the pitch diameter. To draw a gear proceed as follows : The 
figure shows several teeth of a gear having 21 teeth 11.74 inches pitch 
diameter and 1}^ inches circular pitch. The gear is also shown in 
contact with the rack. After the various circles have been drawn the 
pitch circle should be spaced for the pitch points by stepping off with 
a pair of dividers or any other convenient method. 

In the Odontograph table opposite the 21 teeth and under the face 
radius is found the number 1.09. This must be multiplied by the 
circular pitch of the gear and gives 1.907. With the dividers set to 
this face radius of 1.907 draw the face of the teeth from the addendum 
to the pitch circle, keeping one point of the dividers on the base line as 
3 center. If the number of teeth is greater than 36 or if the pitch is 
small, this face radius should be extended to the base line. In the 
case under consideration opposite 21 teeth in the table and in the 
column headed Flank Radius is found the figure .63 and this multi- 
plied by the circular pitch gives 1.102. With the dividers set to this 



GRANT'S EPICYCLOIDAL ODONTOGRAPH 

STANDARD CYCLOIDAI, TEETH — INTERCHANGEABI,E SERIES 

From a Ptmon of Ten Teeth to a Rack 





t OF TEETH 


Fo 
For 


r one D 


ametrical P 


tch 
le by 


For One 


[nch Circular 


Pitch 


NUMBEl 


any other pitch divic 


For any bth 


er pitch mu 


tiply by 


IN TI 


IE GEAR 


that pitch 






hat pitch 






Faces 


Flani 


s 


Faces 


Flanks 


Exact 


Intervals 


Rad. 


Dis. 


Rad. 


Dis. 


Rad. 


Dis. 


Rad. 


Dis. 


10 


10 


1.99 


.02 


—8.00 


4.00 


.62 


.01 


—2.55 


1.27 


11 


11 


2.00 


.04 


-11.05 


6.50 


.63 


.01 


—3.34 


2.07 


12 


12 


2.01 


.06 


QO 


QO 


•64 


.02 


00 


CO 


liVz 


13—14 


2.04 


.07 


14.50 


9.43 


.65 


.02 


4.60 


3.00 


15>4 


15-16 


2.10 


.09 


7.86 


3.46 


.67 


.03 


2.50 


1.10 


nyi 


17—18 


2.14 


.11 


6.13 


2.20 


.68 


.04 


1.95 


.70 


20 


19-21 


2.20 


.13 


5.12 


1.57 


.70 


.04 


1.63 


.50 


23 


22—24 


2.26 


.15 


4.50 


1.13 


.72 


.05 


1.43 


.36 


27 


25—29 


2.33 


.16 


4.10 


.96 


.74 


.05 


1.30 


.29 


33 


30—36 


2.40 


.19 


3.80 


.72 


.76 


.06 


1.20 


.23 


42 


37—48 


2.48 


.22 


3.52 


.63 


.79 


.07 


1.12 


.20 


58 


49—72 


2.60 


.25 


3.33 


.54 


.83 


.08 


1.06 


.17 


97 


73-144 


2.83 


.28 


3.14 


.44 


.90 


.09 


1.00 


.14 


290 


145—300 


2.92 


.31 


3.00 


.38 


.93 


.10 


.95 


.12 


oo 


Rack 


2.96 


.34 


2,96 


.34 


.94 


.11 


.94 


.11 



The table gives the distances and radii if the pitch is either exactly one diametral or one inch 
circular and for any other pitch multiply or divide as directed in the table. 

— [From Grant's Treatise on Gear Wheels 



10-IV 



GEARING 



radius and the center on the base circle, draw the flanks of the teeth 
from tlie pitch circle to the base circle. From the base circle con- 
tinue the flanks of the teeth to the root circle by straight radial liner> 
and round the roots of the teeth with a fillet. 

To lay ofif the rack teeth it is first necessary to draw a straight 
line for the pitch line and two parallel lines for the addendum and 
root lines. The sides of the teeth are drawn through the pitch points 
at an angle of 15 degrees from the perpendicular, as shown in Fig. 4. 

The point of the tooth from the point A Fig. 4 to L> must be 
rounded by an arc drawn from a center on the pitch line and with 
the dividers set to a radius equal to 2.10 inches divided by the diametral 
pitch or the circular pitch multiplied by .67. In the case imder con- 
sideration multiplying .67 by the circular pitch we obtain 1.17 as the 
radius to be used. 

Epicycloidal Odontograph Tables 

Grant has also gotten up an Odontograph table giving the pro- 
portions of epicycloidal teeth. To apply this table in laying out the 
gear shown in Fig. 5 we will proceed as follows : 




Fisr 5. Laying Out an Epicycloidal Gear by the Odontograph Table 

The gear has 21 teeth, 11.74 inches pitch diameter and l-)4 inches 
circular pitch. The pitch circle, addendum and root circles should 
be drawn. The pitch points should also be marked on the pitch circle. 

In the Odontograph table we find opposite 21 under the head of 
circular pitch and the faces of the teeth. .04 as the factor for obtain- 
ing the distance of the circle of centers from the pitch circle. Multi- 
plying the circular pitch by this we have .07 and hence we must lay 
off a circle at this distance inside Ihe pitch circle. 



SPUR GEARS 



11-IV 



The flank center distance for 21 teeth is .5 and multiplying this by 
the circular pitch we have .875 as the distance between the pitch circle 
and the line of centers for the flanks. This circle should be drawn 
as shown in Figf. 5. From the table we find that the factor for the 




GRANT'S INVOLUTE GEAR TEETH PROPORTIONS 



Circular 
Pitch. 


A 


B 


C 


E 


H 


c- 


1 


.33 


.04 


.49 


.08 


.67 


.475 


lys 


.37 


.04 


.55 


.08 


.75 


.534 


1^ 


.41 


.05 


.61 


.10 


.83 


.594 


iy$ 


.45 


.05 


.67 


.10 


.91 


.653 


1/2 


.50 


.06 


.73 


.12 


1.00 


.712 


IK 


.58 


.07 


.85 


.14 


1.17 


.831 


2 


.66 


.08 


.98 


.16 


1.34 


.950 


2% 


.75 


.09 


1.10 


.18 


1.50 


1.07 


2% 


.83 


.10 


1.22 


.20 


1.67 


1.19 


IK 


.91 


.11 


1.34 


.22 


1.84 


1.31 


3 


1.00 


.12 


1.47 


.24 


2.01 


1.43 


3^ 


1.08 


.13 


1.59 


.26 


2.17 


1.54 


iV^ 


1.16 


.14 


1.71 


.28 


2.34 


1.66 


3K 


1.25 


.15 


1.83 


.30 


2.51 


1.78 


4 


1.33 


.16 


1.96 


.32 


2.68 


1.90 


4X 


1.41 


.17 


2.08 


.34 


2.84 


2.02 


4K 


1.50 


.18 


2.20 


.36 


3.01 


2.14 


4K 


1.58 


.19 


2.32 


.38 


3.18 


2.25 


5 


1.66 


.20 


2.45 


.40 


3.35 


2.37 


5K 


1.75 


.21 


2.57 


.42 


3.51 


2.49 


5'A 


1.83 


.22 


2.69 


.44 


3.68 


2.61 


5K 


1.91 


.23 


2.81 


.46 


3.85 


2.73 


6 


2.00 


.25 


2.94 


.50 


4.02 


2.85 


6^^ 


2.16 


.27 


3.18 


.54 


4.35 


3.09 


7 


2.33 


.29 


3.43 


.58 


4.69 


3.33 


7/2 


2.50 


.31 


3.67 


.62 


5.02 


3.56 


8 


2.66 


.33 


3.92 


.66 


5.36 


3.80 


8J^ 


2.83 


.35 


4.16 


.70 


5.69 


4.04 


9 


3.00 


.37 


4.41 


.74 


6.03 


4.28 


9/2 


3.16 


.39 


4.65 


.78 


6.36 


4.51 


10 


3.33 


.41 


4.90 


.82 


6.70 


4.75 



D or distance to the base line equals b's of pitch diameter. 
Note,— Column C is for cast gears. 



12-IV 



GEARING 



face radius of the 21 teeth is .70. then multiplying the circular pitch 
by this factor we have 1.22. With the dividers set to this radius and 
keeping one point on the circle of face centers the faces of all the teeth 
should be drawn. From the table we find that the factor for the radius 




Cleg 

Fillet 

Addemlum- 

— DedeTVlum or root 



— Height of tooth 
-Thickness of iooth- 

— Width of space - 



Fig. f>. Diagram for Tooth Parts 

of the flanks of the teeth corresponding to 21 teeth is 1.63 and multi- 
plying the circular pitch by this we have 2.85. With the dividers set 
to this radius and one point on the circle of flank centers, we should 
draw the flanks of the teeth. Small fillets should then be drawn at the 
base of each tooth, thus completing the tooth outline. 



SPUR GEARS 



13-IV 



Proportions of Tooth Parts 

Grant has gotten up a table of proportions of tooth parts for use 
in connection with his invokite odontograph. For convenience, how- 
ever, in obtaining this information quickly for different pitches, a dia- 
gram like that shown in Fig. 6 may be used. This diagram is for the 
extra short involute tooth and gives proportions of teeth from yl inch 
to 6 inches circular pitch. Such a diagram can be made for teeth of 



Fig-. 7. Jig for Plain Spur Involute Gear 

any proportions, and will be found a great time saver on account of 
the fact that its use reduces the calculations necessary. 

In laying out such a diagram A-B represents the greatest pitch 
required, in this case six inches. The perpendicular B-C is used for 
laying off the various proportions for six inch circular pitch. After 
these points are laid off they are connected with the point A by a 
series of diagonal lines. In order to obtain the proportions for any 
other tooth it is only necessary to erect a perpendicular at a distance 
from A corresponding to the circular pitch desired. In the illustra- 
tion perpendiculars have been drawn corresponding to all circular 
pitches between %. inch and 6 inches, varying by quarters of an inch. 




Fig, 8. Jig for Involute Bevel Gear 

The proportions of this short involute tooth are as follows: Adden- 
dum equals 2-10 circular pitch. Dedendum equals 2-10 circular pitch. 
Clearance equals 5-100 circular pitch, plus one. The thickness of the 
tooth equals 47-100 of the circular pitch. 

Tooth Jigs 

In place of having to lay off the tooth curves or outlines on each 
individual tooth it is best to make a hard wood jig of the exact out- 
line of the tooth and use it in forming all of the other teeth. Fig. 7 
^hows such a jig for a plain spur involute gear and Fig. 8 such a jig 
for an involute bevel gear. It will be noticed that the jig is cut down 



14-IV 



GEARING 



or relieved for a short distance each side of the space which is to 
receive the block for the gear tooth. The opening in the jig to receive 
the block should be the exact length of the teeth across the face of the 
wheel and the blocks trimmed to fit snugly and then secured with 
screws as shown. 

After the block is secured in the jig, a plane may be clamped 
in the vise as shown in Figs. 9 and 10. Blocks should be clamped to 




Fig. 9. Side View of Plane Clamped to Cut Teeth 

this plane at such points that the blades of the plane cannot cut the 
face of the jig. It is on this account that the clearance is provided 
in the face of the jig at each end of the tooth block. Fig. 10 shows 
an end view of the block and plane with the stops removed so as to 
show the dififerent positions assumed by the jig in working out an 
involute tooth. In working out an involute tooth a plane having a 




Fig. 10. End Mew of Plane Clamped to Cut Teeth 

flat face may be used and it is well to make a special plane with a long 
sole so that it will not be necessary to use blocks to piece it out when 
working long teeth. 

When working out epicycloidal teeth it is necessary to use a 
plane having a curved face as shown in Fig. 11, and also to use a 
block or stop on the side of the plane as shown. The curve of the 
face of the plane should be of less radius than the curve of the flanks 
of the teeth. 



SPUR GEARS 



15-IV 



In laying out the wooden block for the spur tooth jig the device 
shown in Fig. 12 will be found very handy for laying off the tooth 
curves. In the device shown the jig for a 16-tooth pinion is being 
laid out. A board shown at A is taken and a slot cut in one end that 
will just fit the jig block. The jig block is placed in position as shown 
with one end flush with the face of the board. The tooth is then 
laid off. After this the jig is removed and placed other end to in the 
slot, when the same centers can be used in laying ofif the tooth outline. 
This insures an accurate layout on both ends of the block and brings 
the layout on the two ends in line. 




Jig Slock 



A 



Fig. 12. Rig for Laying Off Tooth Jig 



Fig. 11. Plane with Curved Face 
for Epicycloidal Gear 

After the teeth for the spur gear have been planed out in jigs, 
they can be tested by placing two of them end to end and seeing if they 
coincide, then reversing both teeth and placing the opposite ends in 
contact. If there is any error in the teeth it will be doubled by this 
method. Care should be taken to have the bottom of both blocks 
planed free from wind and to fit accurately on the outside of the 
cylindrical portion of the pattern. 

Construction of Gear Patterns 

The general method of constructing or building up a gear pattern 
is shown in Fig. 13. The rim should be built up and turned in the 
usual manner with just perceptible draft in the outer diameter. The 



16-IV 



GEARING 



number of teeth should be spaced off before it is removed from the 
lathe. If there is a surface plate available the rim should be laid 
on it and, with the try square, lines drawn across the face correspond- 
ing to the spacing done in the lathe. Placing the try square against 
the rim of the gear is not always a reliable method. 




Fig. 14 shows a common manner of setting the arms together. 
This work can be done very handily on the ordinary bench saw. After 
the arms have been put together, they should be let into the rim as 
shown in Fig. 13 and secured with glue and dowel pins. A more sub- 
stantial manner of securing the arms in place is to build them into the 
rim during its construction. 



SPUR GEARS 



17-IV 



After the teeth have all been jigged out or sanded to form, in the 
manner to be described .later, they should be placed on the rim, the 
root of each tooth being set with its edge in contact with one of 
the spacing lines drawn on the face of the rim. This is a very 
much more accurate method than attempting to space the teeth to a 



x£: 




' ' 




j_r 



Fig. 14. Method of Setting Gear Arms Together 

center line. Each tooth should be glued in place and rubbed down 
so that it fits the line accurately and then, after the glue has set 
slightly, nailed in position. As the work proceeds the teeth should 
be tested with the square and calipers and the work finished by rubbing 
in a leather fillet. 



18-1 V GEARING 

CHAPTER II 

BEVEL AND WORM GEAR PATTERNS 

Bevel Gears 

In the last chapter the making of spur gear patterns and the 
method of jigging teeth for spur or bevel gear patterns was described. 
In this chapter will be described one or two methods of making 
bevel and worm gear patterns which have proven very satisfactory 
in practice. 

The rim of a bevel gear should be built up of segments in a man- 
ner similar to the method used in building the rim of a spur gear, 
except that, owing to the conical form of the rim no two series of 
segments are of the same diameter. Fig. 15 shows the iron faceplate 




Fig. 15. Segments for Bevel Gear Pattern on Face Plate 

of the lathe with a large wooden faceplate B attached to it and the 
section of the rim of a gear built up of four courses of segments as 
shown at A. 

The outline of the rim is drawn on the segments showing the 
amount of stock to be turned off in finishing this portion of the pat- 
tern. After the rim is built up and attached to the faceplate the inside 
surface should be turned and a chuck should then be attached to the 
faceplate B, turned up to fit the inside of the rim, the rim secured to 
the chuck and the outside or face turned ready to receive the teeth. 

It is best to space off the teeth before removing the rim from the 
lathe. Spaces corresponding to the number of teeth should be stepped 
off on the face near the outer diameter. Next attach a block to the 
center of the faceplate, which will project far enough to contain the 
apex of the cone of which the rim is the frustrum. This block is 
shown at A, Fig. 16. The point of the block should be turned so that 
it will form a portion of the surface of the cone, of which the rim 
is a portion. 

Next, take a long lathe rest as shown at D and adjust it so that 
its upper edge is level and on a line with the point or apex of the 



BEVEL GEARS 



19-IV 



cone. If the lathe rest is not long enough a straight edge can be 
attached to it. 

After the rest or straight edge has been adjusted lines can be 
drawn on the face of the gear through the points stepped off near its 




Fig. 16. Face Plate with Blocks at Center of Gear to Form .Apex of Cone 

outer circumference, as shown in Fig. 16. These lines would all 
intersect at the apex of the cone. 

The teeth can then be formed by jigging, as described in the 




Fig. 17. Gear with Part of the Teeth Attached and Arms Fitted 

previous chapter, or by sanding, and attached to the face of the gear 
as shown in Fig. 17. 

While attaching the teeth the work should be removed from the 
lathe, but the gear should not be removed from the faceplate. The 



20-IV 



GEARING 



root of each tooth should be set to one of the radial lines and the teeth 
should be tried with calipers and with the straight edge from the 
apex of the cone, as located on the post attached to the center of the 
faceplate. It will be found convenient to drive a small pin or brad 
into the apex to assist in this work. The arms of the gear should be 




laid out and set in as shown in Fig. 17. At A is shown a section of 

the rim and at B the manner in which the end of the arm joins the rim. 

The method of developing the outline for the tooth at the outside 

and inside faces of the gear, also at the outer and inner ends of the 



BEVEL GEARS 21-IV 

jig is shown in Fig. 18. The work is laid out for a gear having a 
pitch radius of 12 3-32 inches, 38 teeth, 2-inch circular pitch and a 
5-inch face. 

The number of teeth in a bevel gear is the number upon the work- 
ing pitch diameter or radius C-D, but this number is not used in lay- 
ing out the tooth outline. In developing the curves for the tooth, 
the number of teeth in a gear of corresponding pitch and having a 
pitch radius equal to the back conical radius or B-E in Fig. 18 is used. 
In order to lay out the teeth it is first necessary to draw a section of 
one-half of the gear as shown in Fig. 18, the pitch radius of the gear 
being C-D and the face conical radius A-B. 

Next draw a line perpendicular to A-B from a point on the pitch 
line of the gear which is on the line passing through D and at a dis- 
tance from the axis equal to the pitch radius C-D. This line will 
intersect the center line of the gear at the point E, thus giving the 
back pitch radius B-E. Lay off the height or length of the tooth Z, 
and draw radial lines extending beyond the ends of the teeth. 

The spaces X-X correspond to the portions of the jig at each end 
of the tooth and it will be necessary to determine the outline of the 
tooth for both the outer and inner ends of the jig, as well as for the 
outer and inner ends of the face of the tooth proper. With A as a 
center and the radius A-B scribe an arc of a circle and space off several 
teeth with the given circular pitch, lay off the thickness of the tooth 
W and draw radial lines through these points. This will give the 
thickness of the tooth and the circular pitch at the ends of the jig and 
at the smaller end of the tooth. 

It should be noted that all lines on the face of the tooth whether 
at the top, bottom, or any point on the side, including the base line, all 
meet in the apex A. 

With E as a center and B-E as a pitch radius, draw the pitch line, 
and set off several teeth with the given circular pitch. Lay off the 
thickness of the teeth on this pitch line and draw in the addendum, 
root and base circles, the whole to be calculated as explained in the 
previous chapter. 

As the tooth outline is taken from the back conical radius, it 
should be calculated as follows : In the case in hand the radius B-E 
equals 28.61, multiplying this by 2 equals 57.22 inches, as the diameter. 
Multiplying this diameter by 3.1416 equals 179.76 inches, as the cir- 
cumference of the pitch circle used in determining the form of the 
tooth. Dividing this circumference by 2, the circular pitch gives 89.8 
teeth. It should be noted that in dividing the circumference of this 
construction pitch circle, the result will rarely be a whole number. 



22-1 V GEARING 

hence the nearest whole number is taken as the number of teeth. In 
this case 90 should be taken and we would look in the Odontograph 
table opposite this number of teeth for the factors to be used in draw- 
ing the tooth outline. From the Odontograph table the radius to be 
used in drawing the face of the teeth should be found and the centers 
O-O determined. With pitch radius equal to the lines F, G, and FI, 
and E as a center, draw pitch circles for the outer end of the jig, 
inner end of the tooth and inner end of the jig, as shown in Fig. 18. 
Next draw the radial lines I-I through the points O-O which will 
determine the centers to be used in drawing the face of the teeth cor- 
responding to each of these different radii. Of course the addendum, 
root and base circles would be drawn in in each case in their proper 
relationship to the pitch circle. 

When the gear is so large that it is not convenient to determine 
the length of the back radius by a lay out for the large and small ends 
of the tooth and jig, these radii can be calculated in the following 
manner: If it is desired to calculate the back radius B-E correspond- 
ing to a gear having the pitch radius C-D, we would first subtract from 
90 degrees or the angle formed by the intersection of the back radius 
B-E with the face radius A-B, the angle formed between A-B and the 
center line of the gear, which in this case is 65 degrees ; 65 degrees 
taken from 90 degrees will leave an angle of 25 degrees as the angle 
between the radius B-E and the center line of the gear. 

From a table of natural signs take the sign of 25 degrees, w^hich 
is .42262, divide the working pitch radius C-D by this decimal, which 
will give the length of the back radius B-E equal to 28.61 inches. 

Having obtained this radius, calculations are next made for the 
outline of the tooth at the large end as already explained. The outline 
of the tooth at any other point or at the ends of the jig can be calculated 
in the same way. 

In all the calculations for the length of the back radius and the 
outline of the tooth at the ends of the jig it should be borne in mind 
that the number of teeth in any given bevel gear remains the same, no 
matter what radius is used. 

Double Helical Gears 

For heavy mill work double helical gears of the form shown in 
Fig. 19 are frequently used. Considerable care is necessary in making 
the pattern for this class of gear, on account of the fact that the two 
halves of the pattern must be screwed from the sand and any irregular- 
ity in the teeth or body will cause trouble in the molding beside making 
the gears run poorly on account of the fact that if the teeth are not 



BEVEL GEARS 



23-IV 



regular the gears will not mesh correctly. The profile of the teeth 
remains the same as in an ordinary spur gear and is laid out from 
the Odontograph tables. 

In building such a gear as this the cylinder or body is built up 
of segments with an off-set parting line as shown by the dotted lines 
in Fig. 19 (A). This off-set or projection turned on the parting line 
is for the purpose of centering the two halves of the pattern in 
relation to each other. 




Fig. 19. Double Helical Gear 

After the body of the gear is completed, the number of teeth 
should be laid off on the outer edge and also on the inner edge or 
parting, taking care to allow the proper pitch or angle of tooth, which 
is usually 30 degrees. To dress the inner face of the blocks so 
that they will fit the tooth the device shown in Fig. 19 (C) may be 
used. This consists of a box composed of sides E and F and ends G 
?nd H. The block J for the tooth is secured to the ends G and H by 
screws as shown and then the inner face of the block is worked off 
to the curve K. The blocks are left high enough to allow the outer 
diameter to be trimmed slightly after they are in place. 

After the blocks have been fitted to the rim they should be 
secured with dowel pins and screws and then the gear with the tooth 
blocks in place should be returned to the lathe and turned to the exact 
diameter of the points of the teeth. 

From the center of the cylinder or body to the outside diameter of 
the blocks scribe radial lines passing through points stepped off' to cor- 
respond with the number of teeth and with a metal templet cut from 
a piece of sheet steel or zinc, scribe the profile of the teeth on the outer 
and inner end of each block. Remove the blocks from the gear and 
with a flexible rule draw lines from the points corresponding to the root 
and top of the teeth as shown in Fig. 19 (D). Next dress the tooth 
to shape, using the templet to determine the form of the tooth at any 



24-1 V 



GEARING 



point, the templet being guided by the Unes corresponding to the point 
and root of the tooth. The teeth should now be placed back in position 
and secured to the body with screws and dowel pins, but not with glue. 
Then rub in leather fillets. When both parts of the pattern are com- 
pleted they can be placed together and one revolved on the other. If 
the teeth are perfect, they will match at any point. Fig. 19 (A) shows 
a front elevation of the gear and (B) an end view. 

Worm and Worm Gear Patterns 

A right hand single threaded worm and gear are shown in Fig. 20. 
The worm was laid out for a 6-inch pitch diameter to mesh with a 




Section ( 
Rim of Wheel 

30.55"Pitch dia. 

2 Pitch 

18 Teeth 

l)4"width of face 



Fig. 20. Right Hand Single Threaded Worm and Gear 

wheel of 30.55 inches pitch diameter and 2 inches circular pitch. The 
worm wheel contains 48 teeth and has an extreme face width of 4^^ 
inches. The shape of the worm wheel tooth is taken from Grant's 
Odontograph for involute gear teeth. The usual length of tooth for 
this class of gear is 6-10 circular pitch, the addendum being equal to 
275-1000 and the dedendum to 325-1000 of the circular pitch. 

As in practice the worm pattern is usually required to doctor the 
teeth of the worm wheel for clearance it should be made first. The 
pattern is parted longitudinally and is made as follows : Glue up the 
stock and turn the outside diameter with the core prints attached. Do 
not destroy the centers used in turning, as after the thread is cut the 
pattern can be returned to the lathe and revolved at a slow speed while 
the threads are sand papered. 

When the pattern has been turned to the proper diameter and 
length, wrap a piece of drawing paper around it and cut the exact 
length and circumference. Place the paper on a board and lay ofif space 
on each end equal to the circular pitch as shown in Fig. 21. If the 
worm is to be single threaded, draw diagonal lines as shown by the full 
lines. These will represent the pitch of the worm. If the worm is to be 



BEVEL GEARS 



25-IV 



double threaded, draw diagonal lines as represented by the dotted lines, 
each line rising two divisions. If it is to be triple threaded, each line 
should rise three divisions, and so on for any number of threads, the 
angle increasing until the number of threads is so great and the angle 
so steep that we cease to call it a worm and term it a spiral gear. 
If the worm were to be left hand the diagonal lines would rise to the 
left in place of to the right as shown. 




Fifr. 21. Paper Template for Worm 

If the drawing has been done correctly, when the paper is returned 
to the pattern the point 1 will meet point 2, point 4 will meet point 3, 
point 5 will meet point 6, and so on, thus forming a continuous spiral 
line about the pattern. 

After the paper has been returned to the pattern a tracing wheel or 
some sharp pointed instrument should be used to prick the outline 
of the thread through the paper upon the pattern. The paper should 




CORE PRINT 



CORE PRINT 



Fig. 22. Stock Glued Up for Worm Gear 



then be removed and the outline marked in with a pencil. The paper 
may be attached to the pattern either by thumb tacks or by a few spots 
of glue while pricking the outline through on to the pattern. Do not 
cover the entire surface of the paper with glue as the paper would 
stretch and the pitch of the thread be altered. 

The outline or cross section of the worm thread is the same as the 
outline of an involute rack tooth and hence has straight sides, as shown 
in Fig. 20. 

The roughing out of the thread can be done quite closely by clamp- 
ing strips of wood to the sides of a back saw, so as to give the desired 



26-IV 



GEARING 



depth, and then sawing down on the line already laid out. Or the out- 
line niav be formed by revolving the pattern in a V block placed over 
the circular saw. 

After the worm pattern is completed, the stock for the worm gear 
should be glued up and the rim turned to the proper form as shown 
in Fig. 22. The arms should be set in as in spur gears. 

Worm gear teeth may be molded in cores or by parting the pattern 
through the center and screwing each half of it out of the sand. The 
former method the author considers somewhat simpler and hence has 
illustrated it. For this reason the outer face of the pattern is turned 




-ANGLE OF ROOT OF TOOTH 
-ANGLE OF PITCH DIA. 
-ANGLE OF POINT OF TOOTH 



Fig. 23. Laying Out of Worm Gear Tooth 

with draft and core prints to attach to both sides, as shown in Fig. 22. 
If the pattern were made complete it would be necessary to make the 
total number of teeth, while by the use of a core box it is possible to 
get along without forming so many teeth, and thus reduce the work. 
Also, if the pattern is made in halves and the two parts of the mold 
should shift slightly it would deface the teeth. 

There are a number of different ways in which worm gear teeth 
can be laid out and made and there is much difference of opinion 
as to the best method, but the following shows one which practice has 
proven to be successful. Fig. 23 shows the manner in which a block 



BEVEL GEARS 



27-IV 



can be laid out and worked to shape from the solid. The outline of 
the block is shown by the dotted lines. The block should be so formed 
that it will fit the curve of the worm at the top of the tooth and the 
curve of the face of the wheel at the bottom of the tooth. In this case 
the outlines are laid off on the two'ends and connected as shown. 



o « 



^s 




The method of obtaming the angles corresponding to the root 
of the tooth, the pitch diameter and the point of the tooth as necessary 
for the lay out shown in Fig. 23, is shown in Fig. 24. This is done 
by developing the circumference of the worm at the root, pitch diam- 
eter and point of the thread and erecting at one end of each of these 



28-IV 



GEARIXG 



lines a perpendicular equal to the circular pitch. The diagonal lines 
connecting the tops of these perpendiculars with the end of the lines 
representing the different circumferences will give angles as shown. 
Another method of making the tooth is shown in Figs. 25 and 26 
and 27. In this case they are made by turning up rings and cutting 
one tooth from each ring. While this does not give a theoretically 
correct form of tooth it will give one close enough for all practical pur- 
poses. The angle of the tooth is determined as shown in Fig. 24. 




Fig. 26. Rin^ for Making Tooth 



Fig. 27. Face Plate with Center 
Line Drawn on It 



In carrying out this method a faceplate is placed on the lathe and 
the angle piece A, Fig. 25, is attached to it. This should have an 
angle corresponding to the angle of the tooth on the pitch line, that is, 
it should be the same angle as the center line of the thread on the 
paper lay out for the worm pattern. To this block should be secured 
the center disc B which is turned to a diameter equal to the inside 
diameter of the rings shown in Fig. 26 and clamped. Piece C is fitted 
with the necessary dowel pins to properly locate it and also with the 
clamping screw. The rings. Fig. 26, are then turned up to the proper 
cross section, the outside diameter being left somewhat larger than 
required. 

The piece of the ring to be used for a tooth should be cut from 
the portion having the grain running lengthwise, that is, either the 
piece A or B, Fig. 26, should be used. This point must be observed 
in securing the rings in the chuck. 



BEVEL GEARS 



2&-IV 



After the rings are secured in the chuck, the outer diameter is 
turned to coincide with the outer diameter of the worm wheel or the 
segment of the same which is used in the core box. Before the ring 
is removed from the lathe a center line corresponding to the line C-D, 
Fig. 26, should be drawn upon it. 

In Fig. 27 the face plate is shown with the clamp and ring removed 
and with the center line C-D drawn upon it. Fig. 28 shows the manner 
in which the core boxes are arranged with the tooth sections in place. 
The portion of the rim carrying the teeth should be cut diagonally 
as shown at A and B, so as to allow the rim to be drawn back from 




Fig. 28. Segment for Core Box 



the core in sections. In the case of a worm having a very coarse pitch 
the teeth are usually made loose and secured in place by dowel pins 
so that the rim is withdrawn first and then the teeth withdrawn from 
the core. 

No matter whether the teeth of the worm gear pattern are worked 
from the solid block or are turned and shaped, it will be found neces- 
sary to try the points for clearance, as otherwise they will interfere 
when leaving the worm. Fig. 29 shows a way in which the segment 
of the core box or the worm gear pattern can be mounted and revolved 
past the worm for this purpose. The worm being arranged to revolve 
on the centers in its core prints and the segment to swing on a post 
or in any other convenient manner. 



30-IV 



GEARIXG 



Usually it is best to attach two or three teeth first, try them and 
dress them for clearance, and then dress the balance of the teeth to 
correspond with these. 

The following modification may be preferred by some pattern- 
makers and has much to commend it: 




, Fig. 29. Testings Teeth of Segment for Clearance 

To make large worm wheels without making all of the teeth and 
without a core box, make the pattern the same as if you were going 
to core the teeth, placing a core print or clearance piece around the 
outside of the pattern as shown in Fig. 30. Then make a short seg- 
ment of the pattern with a few teeth, as shown. After the pattern is 

Print Cope or Partiag Line 



T 



M. 



HALF SEC. O-a 



Fig. .30. Section of Pattern for Worm Gear 

rammed up and drawn from the mold take the segment, Fig. 30. and 
keeping the shoulder B against the shoulder in the mold left by A, 
step the piece around the mold, marking with flour or parting sand. 
In this stepping off care should be taken to see that you have the 
right number of teeth, as it is very easy to lose or gain a tooth in a 



BEVEL GEARS 



31-IV 



large wheel. After the spacing has been done place the segment at 
the starting point and place a block to make a parting at one end of 
the segment. This block, however, is only necessary for the first 
ramming. 

Sand should then be rammed up opposite the segment and the 
segment screwed out and placed into the next mark, this section rammed 
and so on, until the wheel is finished. This method will often make a 
truer wheel than any made in cores, as there is always a fin where 
cores meet. Then, too, if the cores do not space accurately and have 
to be filed, this will result in either a wide or a narrow space v/here the 
cores meet. 

Sanding Gear Teeth to Form 

In place of the method of jigging the teeth to form with the aid 
of a plane they may be ground to form with a sand paper roller. This 
can be applied to either spur or bevel gear teeth and will be found 
much more rapid than the jigging process and just as accurate. Fig. 31 
illustrates two views and a cross section of the sand roller or mandrel, 

Position of -Tig Sanding Face 
Flank and Btint of Tooth 




Hard Wood Strip E-E ■■" 
Slot D-D 




Fig. 32. Gear Tooth in Jig 



Enlarged Section X-X 
Fig. 31. Sanding Gear Teeth 

with the jig in two positions during the operation of sanding. The 
roller is turned up of any convenient diameter, say 4 to 4^/2 inches, 
with shoulder B-B at one end for guiding the jig. A depression C-C 
of about 1-16 inch in depth and in width a little larger than the length 
of tooth, is now turned down and a piece of garnet paper cut to the 
length C-C and secured to the roller by the aid of the slot D-D and 
strip E-E. This manner of securing the paper to the roller has a 
decided advantage over gluing, as the paper is readily replaced without 
the usual delay waiting for the glue to set. It also avoids the trouble 
apt to occur by the paper swelling or buckling by the moisture from 
the glue. 



32-1 V 



GEARIXG 



The dimensions F-F and G-G, which are of sufificient width to 
give a good bearing for the jig, are now turned down on a Hne with 
the garnet paper, or to the same diameter. The completed jig is 
shown in greater detail in Fig. 32, the opening H-H in the center being 
cut out to receive the tooth blocks. The latter is shown in position and 
is secured in place by two screws. As the bottom of the tooth block 
must conform to the diameter of the rim of the wheel upon which the 




LL 




Fig. 33. Building a Bevel Gear Body 



teeth are placed, so must the bottom of the opening H-H in the jig 
be identical with the same diameter. 

With the jig and roller completed the sanding of the teeth takes 
our attention, and this is a good job for the cub. The tooth blocks 
having been gotten out of sufficient width, both ends are trimmed to 
the exact length and angle, and next with a round sole plane, or the 
bit in the jack plane rounded up. The edge of the block is dressed up 
to conform to the bottom of the opening H-H in the jig. Fig. Z2. The 
tooth block is now placed in the jig and secured with the two screws, 
and after the cutting ofif with a chisel of the surplus material at the 
corners J-J of blocks, the sanding follows in order. 



BEVEL GEARS 



33-IV 



Controlled by the shoulder B-B, Fig. 31, the jig is held against 
the roller and guided over it as it revolves. 

Construction of Bevel Gear Pattern Bodies 

Fig. ZZ illustrates two cross-sections of the rim in the course of 
completion, also a part plan and cross-section of the web. To the left 




Fig. 34. Setting Teeth on a Bevel Gear 



of the center line is shown a cross section of the segment work prior 
to turning, which also shows the manner in which it is built up on the 
face plate, while to the right of the center line is shown a cross-section 



34-IV GEARIN.G 

of the rim at the completion of turning the back or inside of the rim, 
the offset or shoulder K-K being turned down to receive the web. 
A portion of the latter is shown directly over and in position for 
placing into the rim. The three pieces of material, one being shown 
b\ L-L, which form the greater portion of the web, are overlapped 
and secured together with glue and screws. The corners M-M and 
segments N-N are fitted in place and glued. This portion of the pat- 
tern is now secured to a face plate, and the outer diameter turned to 
fit snugly into the shoulder K-K of the rim, in which position it is 
secured with screws and glue. It will be found more convenient if 
this web portion of the pattern is gotten out first and the outer diameter 
turned to shape, and the offset, or shoulder, K-K, in the rim, turned 
out to fit the web, and the latter can then be secured in place before 
removing the rim from the face plate. The back of the rim is then 
given a coat of shellac and sandpapered down and removed from the 
face plate, turned over and centered and chucked directly upon the 
web of pattern, as shown in Fig. 34. This illustration shows one 
manner of accurately placing and securing the teeth upon the rim. 

The face of the rim or the root of the tooth line is now turned to 
the required angle with the aid of a templet, which should extend 
across the entire diameter of the rim. Next attach to the web at the 
center of the work, as shown, the block or post P-P. The post should 
extend far enough out to allow the apex of a cone, of whch the rim 
is the frustum, to be turned at its outer point, S-S. If the face angle 
of rim is correct, the distance R-R from the plane of the pitch diameter 
of wheel to the apex of cone thus formed should be equal to the pitch 
radius of pinion. Spaces corresponding to the number of teeth are 
next spaced off on the face of the rim, near its outer diameter. The 
lines T-T-T are now drawn across the face of the rim through the 
points stepped off and intersecting at the point S-S of post. In placing 
the teeth on the rim, glue is applied to the tooth and the side of the 
tooth is set to one of the lines T, in which position it is held for a 
moment until the glue slightly sets. The sides and top are then tried 
for accuracy with a straight edge, for if the tooth has been accurately 
set, all lines of the tooth should intersect at the point S-S. The spaces 
should also be tried for correctness, with the calipers from the adjacent 
tooth. When all the teeth have been so placed and their correctness 
assured, they are nailed down and a leather fillet rubbed in. With 
the getting out of the hub and ribs and the remainder of the pattern, 
our work is completed. 



SECTION V 

REPRESENTATIVE PATTERNS 

CHAPTER 1 
PATTERN FOR A THROTTLE VALVE BODY 

While all valves are throttles, a throttle valve is generally under- 
stood to designate that design of valve used in regulating or con- 
trolling the steam supplied for reversible engines. These conditions 
usually require a quick action ; hence, the valves are generally operated 
by levers. This necessitates the balancing of the valve so as to counter- 
act the steam pressure, which changes the interior body somewhat from 
that of an ordinary globe valve. 

The valve body illustrated and described in this article is known 
as a three way, 12 x 12 x U^.-in. throttle valve. This particular design 
is frequently used in connection with a pair of heavy reversible bloom- 
ing mill engines. Fig. 1 shows two views of the valve body, and also a 
section on the line A-A ; this section being taken through the intake 
opening. 

To many persons the interpretation of the valve body drawing is 
always a perplexing problem, but this problem has a comparatively 
simple solution, for with the aid of a sheet of carbon paper and piece 
of drawdng paper, the outline of the core can be traced in each view 
together with their center lines. Now by folding these carbon sheets 
along their center lines and placing them in a vertical plane in their 
relative positions, with regard to the accompanying views, the results 
will be surprising, as it will readily be seen what is required and the 
manner in Vv'hich the cores can be made and placed together in the mold. 
Before laying out of a full size section, and the commencing of 
the construction of such a pattern, its position and method of molding 
miist be decided upon. 

This pattern might be parted in the plane of Fig. 2, which shows 
the completed pattern. This would, however, necessitate a loose flange 
and a more intricate core ; or it can be parted as in the case imder 



2-V 



REPRESEN TA 111 'E PA TTERNS 




Fig. 1. Two Views and Section of Throttle Valve 



discussion at right angles to the plane — that is, vertically along the 
line B B, with the bonnet opening downward. This method of starting 
provides a convenient and positive manner of setting the cores as well 
as simplifying the construction of the core boxes. 

Fig. 3 shows the cope and drag parts of the pattern built up 
of segments and ready for turning. These two parts can be dowled 
together or fitted together with a male and female joint. The former 
method probably being preferable, as it does not require the parts to 



A THROTTLE VALVE BODY PATTERN 



3-V 



be rechiicked. After the parts have been turned separately, they are 
placed together, marked, and the dowel pin holes bored. 

The manner in which the opening connections are built up in 
halves and turned is shown in Fig. 4. To avoid a feather edge, and 
also to assist in turning and gluing these parts to the pattern body, 
ample stock is left as shown at C, and afterwards worked off into the 
fillet. The core prints are shown in Fig. 5. The core prints and 
connections could be built up and turned entire, but it is more con- 
venient to turn them separately and attach later. 




Fig. 3, Stock Glued up for Throttle Valve Pattera 

Before proceeding with the discussion of the construction of the 
two core boxes with their detachable parts, let us familiarize ourselves 
more fully with the form and manner of jointing the cores required 
in forming the interior of the body. If the carbon tracings have been 
obtained, as heretofore explained, and are laid out in their relative 
positions to one another, they will appear, of course, without the joints 




Fiar. 4. 



Pattern for Opening Connection Throttle 
Valve Body 



Fig, 5. Core Print for Throttle Valve 



and print portion. The assembled cores, together with a section of 
the mold, are shown in Fig. 6. The two half cores, D and E, forming 
one portion of the body, are made in the same box and are jointed in 
the vertical plain, or at right angles to the joint with core F or the 
parting of the mold. Cores F and G are jointed as shown, and are 
made from the same box — core F forming the drag portion of the 



4-V 



REPRESEXTA TIl'E PA TTERXS 



body while core G forms the cope half of the intake opening. To 
assist in locating- and setting the cores, D, E, and F together in the 
mold, a projection with corresponding depression is formed in the 



joint as shown at H. 




'iectloii I- 1 

Fig. 6. Sections of Cores and Molds 



In placing the cores in the mold, core F, with core G attached 
by pasting and wiring, is set in position. Cores D and E are next 



A THROTTLE VALVE BODY PATTERi\ 



5-V 



secured together in like manner and set upon the ones already placed. 
The plan and three sections of the core box used in forming the 
cores D and E are shown in Fig. 7. The spherical portion of the box 
is built in segments and turned out. It is then flattened off as shown 
to receive the material forming the opening K, and also~ the board 
A B, to which is secured the parts L, Z and M, forming the valve 




chamber. The part M is shown in position in the lower right hand 
section, N O. As these two half cores, D.and E, are made from this 
box, it requires the loose parts to be changed for each core — that is, 
parts L and Z are used in forming core D, while part M is substituted 
for forming core E. 



6-V 



REPRESEN TA Til 'E PA TTERNS 



Prior to the rolling over of this box, when forming core D, part 
Z is removed and piece L drawn back. The depressions left vacant 
by these two parts are filled with green sand to support the over* 
hanging portion of the core while it is being dried. 

It will be observ^ed that the part M consists of a board fitted into 




the spherical portion of the box to flatten it off, and to which is secured 
this portion of the valve chamber. 

Cores F and G are formed in the box shown in the plan and sec- 
tions in Fig. 8 ; the portion R, forming the lower part, being built up 



A THROTTLE VALVE BODY PATTERN 



7-V 



by segments, turned and secured to the frame S, which is built up, 
sawed out and attached to the material T, as shown, so as to form 
the intake opening. This portion of the box is then dressed out with 
the aid of a templet to the proper spherical form as shown by the 
section U V. Plate W is dropped into the top of the box as shown 
to form that portion of the metal thickness of the valve chamber which 
extends beyond the center line of the valve body. 




Fig. 9. Stop-Off used for ForminR Core G 



Print X is suspended in the center of the opening and forms the 
depression H, shown in core F, Fig. 6. Core G is formed in this box 
also with the aid of the stop-off piece Y, which is dropped into the 
box and braced as illustrated in a partial section of the core box 
shown in Fig. 9. 



8-V 



REP RES EX TA Til 'E PA TTERNS 
CHAPTER II 



PATTERN FOR A PINION HOUSING 



Of the accompanying illustrations, Figs. 10 and 11 show one-half 
of an enclosed pinion housing weighing about 28,000 pounds and of 
a design frequently used on modern roll trains. In constructing large 
patterns of this description, when part of the mold must be lifted 
away before the pattern can be drawn, it is often advantageous to 
arrange the mold somewhat after the manner of loam molds, that is, 
with the aid of a cast iron plate or flask, so that the side of the mold, 
usually termed the cheek, can be lifted awav from the seat or bed, 
leaving the pattern free to be drawn. 





^1 I 

I" T 



Li^-l/ 




Fig. 10. Pinion Housing Pattern End and Side Elevations 

When beginning the pattern, it is necessary to lay out a full sized 
plan and cross section upon a good substantial board. The straight 
portion of the pattern is built up of segments, as shown in the upper 
part of Fig. 12. In doing this work care should be taken to saw the 
segments to as near the finished size as possible, so as to reduce the 
amount of finishing to the minimum. If the parts are laid out care- 
fully and band-sawed accurately to lines, it will onlv be necessary to 



A PINION HOUSING PATTERN 



9-V 



clean up or smooth the surface. A Httle care at this point will save 
a great deal of work and time. 

After the parts are built up, the openings for the doors A, Figs. 
10 and 12, are cut out of each side as shown. It will be noticed that 
a flange is necessary at the bottom of the main body of the pattern 
and a fillet piece at the top, as shown by the dotted outlines in the 
upper part of Fig. 12, the flange being shown at B and the fillet piece 
at C. Both the flange and the fillet piece are built of segments turned 
and cut in halves, as shown at the bottom of Fig. 12. The halves are 
then secured to the body in the position shown by dotted lines. The 
intervening space from D to E, between the two halves of the pattern, 
is filled in with segments and dressed ofif to correspond with the 
section of the ends. 




Fig. 11. Half Plan and Half Section of a Pinion Housing 

It is necessary to make a door frame to go around the doors A. 
Three views of this frame are shown in the lower part of Fig. 12 
between the flange and the fillet piece, and, of course, it is necessary 
to make one of these for each of the doors. These parts are built up 
of segments and worked out to fit the body of the pattern, to which 
they are secured. 

The pads to reinforce the flange at the bolt centers are gotten 
out as shown above the door frame. Fig. 12., and secured to the flange 
at the proper points, as shown in Fig. 10. By referring to Fig. 11 
and the dotted lines in Fig. 12, it will be noticed that the inside hubs 
project into the pattern some distance. Fig. 13 shows a plan and 
cross section of this portion of the pattern as it will appear after being 
built up, the parts turned and fitted together. It will be noticed that 
they are joined by a good substantial rapping bar shown at R. The 
space between the two hubs is filled in and worked out into a large 
fillet. The cross supports A and B are used in holding this portion 
of the pattern in place, while the inside of the body is being rammed 
up. To facilitate the ramming of the inside of the body it is necessary 



10-V 



RnrRESEX TA Til 11 PA TTERXS 



to provide a series of oblong openings as indicated b}' the dotted lines 
at HH, in the upper part of Fig. 12. One-half of each of these open- 
ings is shown on the iiiibs in Fig. 13, and the other half on the portion 
of the fillet piece shown in the lower left hand corner of Fig. 12, the 
half openings in each case being indicated by the letter H. 




Fig, 13. Interior Hubs 



Fig. 12. Body of Pattern. Flange, Fillet 
Piece and Details 



The body portion of the pattern is now completed and building 
the web is next in order ; to facilitate the handling and storing of this 
part of the pattern, it may be made in halves with a longitudinal joint 
through the center and the halves lined and bolted together while 
being molded. 

One-half of the partially completed web is shown in Fig. 14, 
illustrating the manner in which it is built up of segments and one 
side closed. After the two halves of the web are completed, they are 
pinned and bolted together and dressed ofif. 

The two outer hubs required are shown in Fig. 15, built up and 
turned ready to be placed in position and secured by dowels. 

The feet of the housing must be also be gotten out and secured in 
the same manner. The details for this portion of the work are shown 
in Fig. 16, the three figures at the top showing the 'details of one foot. 



A PINION HOUSING PATTERN 



11-V 



There would be one of these parts required for each hand, that is, 
right and left for each half of web. It will be noticed that the pro- 
jecting lip at the lower portion of the foot is secured with loose pins 
so that these parts can be drawn into the mold after the main portion 
of the pattern has been removed. The foot for the opposite side of 




i_i J 




Fig. 14. Web Portion of Pattern Lagged up 



Fig. l.S. Outer Hub 



the web is shown in detail in the three views in the lower part of 
Fig. 16, and it will also be necessary to make two pieces of this, one 
right and the other left hand. These two parts of the foot, together 
with the intervening thickness of the web, give the desired bearing 




Fig. 16. Foot of Housing, 



for the foundation of the housing. It will be noticed that in the piece 
shown in the lower right hand corner of Fig. 16 there is a parting 
along the line BCD, and that the intervening space between this 
joint and the body is filled in and worked out in the fillet as shown. 



12-\- 



REPRESEN TA TIl^E PA TTERNS 



After the top or cope side of the web has been finished it is turned 
over with the open side up and the body of the pattern placed upon it, 
located, and secured in place with dowels. The portion of the foot 
shown by the three views at the bottom of Fig. 16 is also placed and 
secured with screws and pins. The portion of the web extending 




Fig. 17. Web Portion of Pattern Completed 

outside of the body and up to the fillet of the foot is now filled in with 
material of the necessary thickness to give the required thickness of 
web as shown in Fig. 17, the partial cross section on the line X X 
indicating the thickness of the pattern at that point. 

A cross section of the finished pattern taken along the line M N 
O P, Fig. 10, is shown in Fig. 18. This also shows the manner in 




Fig. 18. Section of Finished Pattern 

which the trunnions are turned and fitted to the pattern, being secured 
with loose dowels and pins. 

A plan and section of the core box for making the cores for the 
two babbitted bearings in the hubs is shown in Fig. 19. The core 
prints shown in the core boxes ar to receive the dovetailed cores 



A PINION HOUSING PATTERN 



13-V 



made in the core box shown at the bottom of Fig. 19, and intended 
for forming the rests or anchorage for the babbitt, as shown in the 
cross section of the casting in Fig. 11. 

When molding the pattern, a hole is dug in the floor to such a 
depth that it will bring the parting line of the cope about level with 
the floor and a level bed is struck off. The body of the pattern is now 
placed upon the bed and the inside rammed up to about the height of 
the bosses. The bosses secured to the supports A-B, shown in Fig. 13, 
are then set in place and screwed down. If a cast iron plate with 
suitable lifting lugs and an opening in the center, conforming some- 
what to the outline of the body, is to be used for supporting and 
lifting away the cheek, it is now lowered over the pattern and placed 
upon the bed, and the ramming up of the cheek is the next operation. 




Fig. 19. Core Boxes for Bearings 



During the operation of ramming up the cheek, and when this portion 
of the mold is nearly completed, the web portion of the pattern with 
the lower feet secured to it, is placed upon the body, the trunnion set 
in place, and the ramming of the cheek completed, up to the parting 
for the cope. The inside of the mold about the hubs must also be 
rammed up to the oblong openings. The supports for the inner hubs 
are now removed, and the outer hubs and upper part of the foot set 
on the web. The cope is then placed in position, rammed up and 
lifted off in the usual manner. The web of the pattern is then drawn. 
The cheek is next lifted away, so as to leave the body of the pattern 
exposed and free to be lifted from the core. The mold is now dressed 
and skin dried, when it is ready to assemble. The gates and runners 
are prepared, the mold assembled, and is then ready for weighting 
down and pouring in the usual manner. 



14-V 



REPRESEXTATIVE PATTERNS 
CHAPTER III 



HAWSER PIPE PATTERNS 

Hawser, or "hawse" pipes, as they are generally called, are usually 
made in pairs, consisting of a right and left hand pipe. The length 
of the pipe, its diameter, and the angle of the ends, are governed by 
the angle upon which the pipes are set with the deck, by the outlines 
of the hull and the size of the anchor chain. 

The pipe with the out board flange is cast entire, as shown in Fig. 
20, while the deck flange as shown in Fig. 20 is cast separate and 
subsequently riveted upon the deck. These pipes are usually of cast 




Fig. 20. Hawser Pipe 



Fig. 21. Bow of Hul 



iron and their construction affords a very good example of what may 
be termed cross templet and hollow pattern work. 

It will readily be seen that this form of templet and method of 
making a pattern can be used in a very large number of ways for 
special pipes, etc. The outboard opening of these pipes often assumes 
different forms, to accommodate the stock of the anchor. In some 
cases the pipe flares outward in the form of a bell. When this is the 
case, it requires a complete pattern parted longitudinally with the 
inside, worked out to form the desired metal thickness. The inside of 
the pattern then serves as a core box for forming the green sand core, 
the core being lifted out with the aid of a core bar or skeleton. 



HAWSER PIPE PATTERNS 15-V 

To illustrate more fully the position and arrangement of these 
pipes when in place, two views of the bow or forward part of the hull 
are shown in Fig. 21. 

The customary practice in most ship yards for transferring the 
angle of the deck and the hull to the pattern is as follows: The pat- 
tern is made solid or lagged up, and of about the required length. It 
is then shoved down through the openings provided in the deck and the 
hull and secured in place. The outline of the opening is next scribed 
around the pattern and is dressed off while in this position. Material 
equal in thickness to the contraction in the length of the pipe is added 
to one end. Next a core print is dressed off to conform to the angle 




Fig. 22. Three \'iews of Cross Templet 

of the deck and attached to the pattern. Any patternmaker who has 
been so unfortunate as to fall heir to this particular job will agree 
with the writer that the method illustrated and to be described is far 
superior to the method mentioned. 

The form of templet used in connection with this method is termed 
o cross templet, as a cross section of the templet would be in the form 
of a cross, as shown in Fig. 22, which illustrates three views of the 
templet during the three stages of its completion as applied to the 
hawse pipe pattern. At the left in the figure is shown the templet 
nailed and bracketed together, and ready for the next operation which 
is the cutting of the angle on the ends. To cut the angle on the ends 
the templet is shoved down through the opening on the deck and out 
through the opening in the hull and clamped in position. The ends 
are next sawed off and dressed to conform to the angles of the deck 
and hull. The templet would now appear as shown in the central view 
of Fig. 22. The work thus far is done by the templet maker, who 
now turns it over to the patternmaker. 

The separate parts of the pattern are shown in Fig. 23. At the 
right and left of the figure are the two barrel or cylindrical sections 
which have been sawed and dressed to conform to the angles of the 
ends of the templet which is shown in the center of the figure. These 
two cylindrical ends of the pattern are lagged and glued up over 



16-V 



REPRESENTATU'E PATTERNS 



cylindrical heads having a diameter equal to the inside diameter of 
the pipe. A dry joint is left in the lagging on each side to permit the 
removal of the pieces from the heads and the cleaning of the inside 
of the pieces. The outer diameter is next turned to size, the lagging 
being secured to the circular heads with screws, which are removed 
as soon as the turning is completed. The heads are then taken out 
and the inside of the lagging cleaned up. The cylinders are then glued 
together as shown at the right and left of Fig. 23. 

The templet being made of the same diameter as the outside of 
the pipe necessitates the cutting down of each end of the templet as 
shown at A, to allow this portion of the templet to enter the inside of 
the pattern. The ends are then slipped over the templet and secured 
with screws, the cylindrical ends being dressed off to conform to the 




Fig, 23. Separate Parts of Pattern 



angle of the templet as shown. Of course, allowance has to be made 
for the shrinkage of castings and this is accomplished by nailing strips 
on one end of the templet as shown at B, Fig. 23, the thickness of these 
strips being equal to the shrinkage which would take place in the 
length of the pipe. At the top of Fig. 23 is shown a core print which 
is attached or inserted into the end of the pattern which is without a 
flange, that is, the deck end of the pattern. This core print is lagged 
up in the ordinary manner and the outside turned to the proper diam- 
eter. If the inside diameter of the pattern has been lagged up care- 
fully the core print should slip into it snugly. Of course, it is neces- 
sary to make some allowance for clearance. The slots shown at C 
in the core print must be cut to allow the core print to slide past the 
templet. A temporary head is used in the upper or open end of the 
core print when lagging it up and turning it and is subsequently re- 
moved, after which the slots are laid out and sawed to suit the templet. 
The assembled pattern is shown in Fig. 24, in the correct position 



HAWSER PIPE PATTERNS 17-V 

for molding. It will be observed that the pattern is so placed as to 
cause the flange to set in a perpendicular position, this being necessary 
to allow the coping off of the flange end of the pattern. 

The flange, ready to attach to the pattern, is shown at the bottom 
of Fig. 23. It is built up in segments and worked out to form, being 
parted along the line D D, so that the upper half can be allowed to 
lift off with the cope when molded. Loose dowel pins are used to 
secure the entire flange in position. A chipping strip E, Fig. 24, of 




Fig, 24. Assembled Pattern 

about one inch in width and ^ inch in thickness is attached around 
the outer edge of the flange with loose pins. The object of the chipping 
strip is to facilitate the fitting of the flange to the hull. Where hawse 
pipes are of the same diameter, one templet may be made to serve 
for several pipes, or the circular end may be readjusted upon a templet 
trimmed to the new angle and the old pattern thus made to serve for 
more than one vessel. 

Molding of the Pipe 

The molding of this pipe contains some points of interest, par- 
ticularly in connection with the checking oft' of the flange end. A plan 
and two cross sections of the completed mold are shown in Fig. 25. 
At the top of the illustration is shown a plan of the mold with the 
pattern in place ready to have the flask placed in position for ramming 
the cope. At the right is shown a cross section through the cheek on 
the line F F, while at the bottom of the figure is shown a longitudinal 
section of the complete mold on the line G G. In beginning this 
work provision is first made for checking oft' the end containing the 
flange, after which the pattern is bedded in. During this operation 
that part of the mold occupied by the open space H between the two 
lagged up ends of the pattern is made up by ramming the sand about 
the pattern at the ends, removing the pattern and striking out the 
central portion with a straight edge to conform to the rammed up 
portion. Parting sand is now applied to this struck off surface and 
the pattern returned to place. A parting is next made around the 
pattern and up to the line of the cheek. Sand is used to fill up the 
opening H in the cope, the sand being struck oft' to conform to the 
ends as shown. 



18-V 



REP RES EN TA TITE PAT TERNS 



A bed is made to receive the cast iron lifting plate I which is 
dropped in place. For illustration a plate of triangular form is shown, 
but the shape and size of the plate is generally governed by the avail- 
able material about the foundry. The flange which is not fast is now 
secured to the pattern with loose pins and the ramming up of the 
cheek commenced. A parting is made at the rounding surface of 










^\ri-/S:if Sectlo,ir-F 



•-^>?< 



Farting 



^?P 



Yi«. 25. Plan and Secti m of Mold 



Coat Iron Flat* I 



the flange above the parting of the mold as shown. A parting has also 
to be made along the line of the joint of the dry sand core in the 
cheek. This is accomplished by ramming sand into the end of the 
pattern and making a parting by striking it off even with the pattern. 
This parting is then covered with paper while the cheek is being 
rammed. 

The cope is now placed in position and staked dow^n. It is then 
rammed up and lifted off in the usual manner. The upper half of the 
flange lifts oft' with the cope. The cheek is next slightly lifted and 
drawn forward in the direction of the arrow, allowing the lower 
flange to be drawn back out of the cheek. The body of the pattern 
is then free to be drawn, with the exception of the point J, which 
necessitates a slight longitudinal movement of the pattern toward the 
cheek to allow this point to clear before the pattern is drawn from the 
mold. 



HAWSER PIPE PATTERNS 19- V 

The mold is then dressed in the usual manner, the cheek moved 
back into position and backed up by ramming the sand behind it. The 
dry sand core which forms the interior of the pipe and which is con- 
structed with the aid of a frame and angle box, is now set in position 
upon chaplets and butted up to the cheek as shown. The cope is placed 
on, weighted, and the mold prepared for pouring. This entire mold is 
made in green sand, with the exception of the dry sand core mentioned. 



20-V 



REPRESEXTA Til 'E PATTERXS 
CHAPTER IV 



A NOZZLE PATTERN 

Nozzles or saddles are usually employed in forming connections 
with shells or similar boiler work, and are made in various forms and 
sizes. The illustrations show a common form of nozzle. The pattern 
work and the operation of molding a piece of this shape is of a com- 
paratively simple nature. It may contain some points of interest, as, 




Fig. 26. Nozzle Casting 



for example the plugging of impressions to receive cores when core- 
prints cannot conveniently be used, also another feature is the arrange- 
ment of the three-part flask. 

Fig. 26 shows a nozzle casting as it would appear ready to be 




Coie-piint 



Plug 



7. Nozzle Pattern Assembled 



riveted to the shell. The assembled pattern is in two parts and 
appears in Fig. 27. This illustration gives the general construction, 
which of course is segment work, also the location and formation 



A NOZZLE PATTERN 



21-V 



of the joint, the latter being shown in greater detail at the left. It 
will be observed that the entire draft of the inside diameter of the 
pattern is in the direction of the arrow, while the draft on the outside 
diameter of the pattern is toward the joint. 

As the upper part of the pattern is a simple lathe operation, we 
will discuss only the turning and working out of the lower portion, or 
that part of the pattern containing concave flange. To the left of the 
center line in Fig. 2'^ is shown a cross section of the first operation, 
that of building the ring up in segments. At the right of the center 
line is shown a cross section of the piece after having passed through 
the operation of turning and of fitting the joint. 

Next the concave surface must be dressed out. This can be 
accomplished very nicely and accurately by nailing together a light 





Fig. 28. Details of Saddle Flange Construction 



Figr. 29. Working of Saddle Flange to Form 



frame of the proper depth, the two ends of which are cut out to the 
required radius of the flange. The frame is now tacked down on 
the work table, and the work dropped into it, secured and dressed 
out to conform to the circular ends of the frame. A cross section of 
the flange would now appear as shown to the right of the center line 
in Fig. 29. 

The thickness of flange is scribed around the outer diameter, 
and the dressing of the flange to thickness accomplished with the 
gouge and calipers. When this operation has been completed, a cross 
section of the flange would appear as shown to the left of the center 
line in Fig. 29. 

x^s the outer diameters of these flanges are usually made on a 
radial line with the center of the shell upon which they are placed, 
this will cause the edge to be irregular ; it must be laid out on the 



22-V 



REPRESENT A Til 'E PA TTERNS 



concave side of flange and dressed off with the aid of a templet and 
the eye. 

A handy little tool for laying off or scribing the width of the 
flange and rivet circles is shown at the top of Fig. 29. The gage is 
applied and guided by the inside diameter of pattern. 

Next the rivet centers are stepped off around the rivet circle and 
holes radiating toward the center of shell are bored. The diameters 
of these holes are equal to the diameter of the cores to be used. A 
plug, shown in greater detail at the right in Fig. 27, is turned up to 
fit these holes, the shoulder allowing it to project through the flange 
the desired distance. 

In molding the pattern the section of pattern containing the 
straight flange is placed upon the follow-board in the reversed position 



:::'^S''?'':^''!ili''^^^ 




Fig. 30. Section of Mold 



as shown in Fig. 27, and the cheek placed over it. This is followed 
by the operation of ramming up the inner and outer diameter until the 
joint of the pattern is reached. The balance of the pattern is now put 
in place and the ramming of the cheek completed with a parting made 
around the outer edge of the flange as shown in Fig. 30. The drag 
is now located and rammed up in the usual manner. These two 
parts of the mold are now clamped together, rolled over and the part- 
ing for cope made. At the completion of its ramming the latter is 
lifted off. The upper section of the pattern drawn, the cheek is 
lifted off, the depressions to receive the cores formed with the plug 
shown in Fig. 27, leaving the concave flange portion of the pattern 
free to be drawn up over the center core which is formed by the 
inside diameter of the pattern. The mold is now dressed, the cores 
set and the parts of the mold returned to place and clamped together 
as shown in Fig. 30. 



STEEL TRUCK BOLSTERS 23-V 

CHAPTER V 

MOLDING CAST STEEL TRUCK BOLSTERS 

The truck bolster shown in Fig. 31 is that of the American 
Steel Foundries and the drawings also show their method of molding 
it. Green sand molds are employed in the production of practically 
all of this class of work. This is true whether the bolster pattern be 
mounted on a stripping plate machine, as in the case under discussion, 
or be molded upon the floor. 

The method of molding is comparatively simple, but affords a 
very good example of the ramming up of a green sand core in place. 
This operation may be applied to very good advantage in a great 
variety of ways, especially in die producing of light steel castings 
where the presence of dry sand cores is to be avoided if possible, 
owing to their tendency to retard the shrinkage, as this shrinkage is 
apt to result in a badly strained or cracked casting when resisted by 
hard cores. This method may save some of the expense otherwise 
incurred in the making up of dry sand cores and in the handling of 
the same. 

The success of the patternmaker in dealing with any problem of 
this kind depends wholly upon his ability to see how the object or 
pattern to be made will appear and how it may be molded in the most 
practical manner. With these two points constantly held clearly in 
mind the construction of the pattern becomes a secondary consider- 
ation. For this reason the writer believes that large returns often 
result from time spent over a drawing in studying every detail and 
getting a thorough idea of what is desired by the draftsman and what 
is required in the way of material, etc. When beginning any pattern, 
whether it is to be mounted on a machine or molded on the floor, its 
position and manner of molding must first be determined. 

The truck bolster to be molded is shown in several views in Figs. 
31 and 32. At the top of the illustr:.tion, Fig. 31, is shown a half- 
side elevation and half-longitudinal section on the center line of the 
bolster. At the bottom of the figure is shown a half-top and half- 
bottom plan, while Fig. 32 shows two cross sections of the bolster 
on the lines A- A and B-B, Fig. 31. The section A-A gives a cross 
section of the bolster at the middle through the center plate, while a 
section through the side bearings is shown at B-B. The stripping 
plate line or the line of the parting is located at C-C, Figs. 31 and Z2. 

In beginning the work, let us first take up the construction of 



24-V 



KEF RES EX TA Til 'E FA TTERXS 




(I* fn 



STEEL TRUCK BOLSTERS 



25-V 



the cope and drag portions of the pattern, as shown in their mounted 
position upon the molding machine, Figs. ZZ and 34. These parts 
should be made of hard wood, maple preferred, although in some cases 
pine is used. The parts should be substantially put together and the 
corners protected by light angle iron as shown. Fig. 33 illustrates 
the cope portion of the pattern, which, owing to its shallowness, is 
usually n.iade solid, the material being glued up edgewise, as shown 
at the right in the cross section of the pattern on the line D-D. 
This section is taken through the depression in the pattern which forms 
one of the openings in the top of the bolster. In other words, these 
openings in the top of the bolster are depressed in the pattern to a 
depth equal to the metal thickness of the top of the bolster. These 



Fig. 35 



© 



© 



Steel Plate )i' Thick 

© © 



© 



Flask Fin Plate 




wn 



Section T-'X' 



Fig. 35. One Quarter of Steel Strippin§r Plate Fig. 36. Plan of Wooden Stripping Plate 

depressions or openings thus form their own green sand cores during 
the operation of molding. 

Temporary patterns are made for the center plate G, side bear- 
ings H, and guide flanges F, these parts being made of cast iron fitted 
or turned up and subsequently properly located and secured in position 
upon the pattern. 

The drag portion of the pattern is shown in Fig. 34. This portion 
of the pattern is constructed as a box section as shown at the right 
in the cross section on the line E-E. The two ends of the pattern 
are practically built in solid, to allow for the forming of the core print 
at each end. 

In constructing this portion of the pattern the sides may be gotten 



26-V 



REP RES EST A Til 'E PA TTERXS 



out about 2y2 inches thick, laid off, sawed and dressed to form. This 
portion of the pattern, as well as the cope portion, should extend about 
two inches below the stripping plate line. After the two sides have 
been placed upon a level surface and squared up, they are secured 
together with separating pieces and the two ends filled in solid. The 
top is next filled in and dressed off to conform with the sides. As 
the two oblong openings in the bottom of the bolster are formed by 
a dry sand core with a core print setting, these two core prints J are 
gotten out and secured in position as shown, as is also the center pin 
core print K. With the binding of the corners of the pattern with 
angle iron and the securing of the guide tianges F in position, this 
portion of the pattern is completed, after it has had the usual applica- 
tion of shellac. 



Fig. 37 

/Holding Don n Corei x 




Fig. 38 ^' 

Section y-N 

Fig. 37. Section of Mold Fig. 38. Rie (or RaniminR up the Green Sand Core 

As the mounting of the pattern upon the machine depends entirely 
upon the raising and lowering operation and the arrangement of these 
parts of the machine we will not discuss that part of the work, but 
proceed with the fitting on of the material forming the stripping plate. 

In most cases a steel plate about y2-mch in thickness is used, but 
the writer has fitted up molding machines for this class of work with 
a pine stripping plate about 1 ^-inches in thickness, the lumber being 
substantially cleated together, and has found that such stripping plates 
have successfully withstood the action of pneumatic rammers in the 
production of several hundred castings. 



STEEL TRUCK BOLSTERS 27-V 

If it is determined to equip the machine with a half-inch steel 
stripping plate, the pattern is located and secured in its correct posi- 
tion upon the operating device. A wooden templet is next gotten out 
and fitted up to the pattern. While in this position the outer edges are 
dressed ofif to conform to the outer edge of the flange of the frame, 
also the longitudinal and cross center lines are laid out, as the plates 
must meet at these points. One of the quarter plates is illustrated in 
Fig. 35. 

These plates are gotten out in four pieces by punching and 
chipping to the outline of the templet, after which they are secured to 
the flanges of the side frames of the machine with countersunk head 
screws. 

The center line of the pattern is next carefully tried for exactness 
and the templet for drilling the flask pin holes applied. This operation 
should be very carefully conducted, as the matching up of the cope and 
drag portions depends entirely upon the care with which it is per- 
formed. 

Should a wooden stripping plate be desired, material equivalent 
in length and width to the top of the side frame flanges ma}- be 
cleated together in a temporary manner and the pattern placed in its 
correct position upon it. With a small pair of dividers set to about 
1-16-inch a parallel line is next scribed around the pattern. The cleates 
are then removed and the material enclosed by the scribed lines sawed 
out. Permanent cleates are next applied and the whole secured to- 
gether. To protect the edge of the opening and to insure a closer 
joint around the pattern without a large bearing surface, 1 3^ -inch by 
^-inch band iron is laid in around the opening, as shown in the plan 
and elevation, Fig. 36. 

The pattern having been secured to the machine, the plate or top 
is set down over it and secured to the side frames with bolts. Plates 
containing holes to receive the flask pins are now located by the aid of 
the flask pin templet as previously stated, these plates being let down 
flush with the top surface and secured with screws as shown. 

With the machine fitted up, our attention is next given to the 
matching up of the cope and drag portions of the mold. The most 
satisfactory manner of ascertaining this fact and detecting any dis- 
crepancy is to have two or three castings made and check them up 
carefully. The making and checking of one casting is not always 
reliable, as a little variation in the flask pins may make it appear as 
if the setting up of the machine was not correct. 

The drag portion of this pattern is mounted upon a roll-over 
machine, that is, a machine which is inverted with the flask in place 



28-V 



REP RESENT A TIVE PA TTERXS 



and the pattern subsequently drawn up out of the sand, this being- 
necessary on account of the fact that no bars are used in the drag 
fiask and hence it cannot be Ufted off and rolled over. The attaching 
of the flask to the machine of course changes the center of gravity of 
the machine. For this reason two trunnions are required, as shown 
at the right of Fig. 34, the fixed trunnion M being employed when in- 
verting the machine with the flask attached, while the attachable trun- 
nion, N, which is secured to the end frame with a pin and socket, as 
shown, is used in returning the machine to its upright position when 
the flask has been detached. 



c 




-^ y^ 




/ 






7 


_^ 




5^ 


■^ 


L 




- 




^?;i;-.^Cx 



Section H-M 



Section G-G 



Fig, 40. Core Box for Forminfr Core B 



Everything being in readiness we will now proceed with the mold- 
ing of the drag portion of the pattern. The pattern is first raised and 
locked in position as shown in Fig. 34. The flask is placed on and 
securely clamped down to the flange of the machine, a thickness of 
prepared sand is applied over and tucked around the pattern. The 
balance of the flask is filled with heap sand, which is rammed in, the 
top being struck off in the usual manner. A bottom board is next 
applied and clamped down, and this is followed by the rolling over 
of the machine and the drawing of the pattern as previously described. 

The next operation is the setting of the several dry sand cores 
which form the metal thickness or bottom member of the bolster. 
Before proceeding further it will be well to study Fig. 37, which 
shows the manner -in which these different cores are placed together 



STEEL TRUCK BOLSTERS 



29-V 



in the mold. In setting the cores, the cores A, which form the two 
oblong openingfs in the bottom of the bolster, are first placed in the 
depressions left vacant by their respective core prints J. 

It will be observed that these two core prints J are provided with 
projections P, which might be termed dowels. These serve to locate 
and secure the center core B in its correct position and also one end 
of each of the cores C, the outer ends of the latter mentioned cores 
being received by core print settings as shown. 

When these five cores have been located, the holding-down cores 
E are placed in position, directly underneath or opposite the depres- 
sions in the cope pattern which form the openings in the top members 
of the bolster, as shown in the cross section of the mold on the line 
L-L, Fig. Z7. 




Section t/'-iT" 

Fig. 41. Core Box for Forming Core C 



These two cores E are rammed up in the green sand core and 
are used to prevent the dry sand cores at the bottom from rising, due 
to the pressure of the metal exerted underneath the cores as the mold is 
poured. 

The method of ramming up the green sand core is illustrated in 
Fig. 38. It will be noticed that there is a frame used for ramming up 
the green sand core, the construction being made clear by the illus- 
tration. The center part O which contains the center post and vertical 
ribs of the bolster is made detachable and secured to the frame with 
dowels, this being done to allow this part to be drawn first, so that 
the top of the green sand core may be slicked and dressed up before 
removing the frame proper. The core is rammed up as follows: 



30-V REPRESENTATIVE PATTERNS 

After the dry sand cores are set, as already explained, the frame 
without the center, Q, is lowered into the mold so as to rest upon the 
parting. The material R passes down into the space between the wall 
of the mold and the dry sand cores as shown by the dotted lines in 
Fig. 37, thus closing up this space and preventing any sand falling 
into it during the ramming up of the green sand core. The center 
part O of the frame containing the center post, etc., which passes 
down into the depression in the core B is also located. 

The depression in the core B is formed by the material in the 
core box shown in Fig. 40. The openings U, Fig. 38, are to facilitate 
the ramming of the sand underneath the top portion of the frame. 
After the sand has been rammed into the green sand core frame the 
top portion Q is removed, the surface slicked up, and then the other 
portions drawn away so as to leave the green sand core in place. 

As the molding of the cope pattern shown in Fig. 33 is of a 
simple nature and embraces no special points of interest, we will 
proceed to discuss the construction of the core box employed in form- 
ing the various cores. Fig. 39 shows a plan and cross section of the 
core box used in forming core A, which gives its construction and the 
manner of parting. In Fig. 40 is illustrated a plan longitudinal and 
cross section of the core box used in forming the center core B. It 
is in this box that the portion of the center post, with its ribs, is formed 
by the material S, the remaining portion being made up in the green 
sand core as explained previously. Within this box is also placed a 
portion of the reinforcement around the oblong opening, the remain- 
ing portion being placed in the core box shown in the plan and cross 
section in Fig. 41. This latter box is employed in forming the two 
end cores C, which are identical, with the exception of the runner T, 
which is rammed up in one core only. The center pin core D, the 
holding-down cores E, and the side bearing cores F are formed in 
their respective core boxes, as shown in Figs. 42, 43 and 44. 



CYLINDRICAL CASTINGS 
CHAPTER VI 

RIG FOR PRODUCING CYLINDRICAL CASTINGS 



31-V 



The mold for a cylindrical casting like that shown in Fig. 45, may 
be produced without the use of complete patterns or sweeps, as de- 
scribed in this chapter. The parallel portion of the cylindrical body 
is made with a cast iron ring similar to the ring used in molding 





Fig. 45. Cylindrical Casting 



pulley rims. While this method of drawing up a ring to produce a 
pulley rim or other cylindrical shell is not new by any means, it may be 
of interest to some and serve to show how this manner of molding can 
be applied to different pieces. 

A section of the mold is shown in Fig. 46. In beginning this it is 



32-V 



REPRESENT A Til 'E PA TTERNS 



at first necessary to dig a pit having a depth about equal to the length 
of the desired casting and of such diameter that it will allow a molder 
to work around the outside of the rim when ramming it up. A level 
bed is then struck ofif in the bottom of the pit and a good substantial 




liiSi 



(iMi 






giaiE 



iM ivyjiiMairiHiiiniiiiirii 






%tfliil 

ik 



m 



VENT VENT^, 

mtmsml 



ti((,"r;i' 



Mm 



fiiii\\iiri/i(|(;\\.M(fiM(--l-i' 



m 



i|isil!l , 

m 



'immmmiim 



^m\{ 






(/mil 



Sl)li""( i|IIJ/l!l(i 






m 



J (It 
Iff 



li^ mii'im 













mmWm 

IMS 

'(^IW If \\ 1\ 



'immm 



^(i' 111 

i'D) '"''! 
Ill //.'ii,, 



miilims 






\l 



III'III'IHII, 

MB 



Mill* 



mm 

mm 












ma 



m 



sMiillS 



ill' 1 



^////(///((i(miii',')iu'i',(iiif 



Fig. 46. Section of the Mold 



stake driven in the center of the same. The stake should be of such a 
length that that portion projecting above the bed will be equivalent 
to the length of the desired casting. The distances A and B from the 



CYLINDRICAL CASTINGS 



33-V 



top of the stake to the under side of the cores forming the top and 
middle flanges, is then scribed around the stake as a gauge for drawing 
the ring to these heights, which correspond to points at which beds 
must be struck off to receive these cores. 

A cast iron ring of the required diameter and thickness and having 
a width or face of 6 or 8 inches is then placed upon the bed with the 
stake about in the center. A number of round sticks 12 or 14 inches 
in length are then driven around the inside to form the vents shown 
in Fig. 46. The inside of the ring should then be rammed up for 
several inches so as to insure its remaining in the required position. 
The cores C forming the lower flange are now set up to the ring and 
the outside and the inside firmly rammed to the top of the ring. This 
portion of the mold is then thoroughl}^ vented and the ring and vent 




LOOSE IN BOX 



Fig. 47. Core Box for the Trunnions 



Stakes drawn up several inches. The operations of ramming and vent- 
ing are repeated. During these operations some iron rods or core 
irons should be set inside of the ring to hold the central portion of the 
mold or green sand core in place. These would be parallel with the 
rods forming the vents shown in Fig. 46. A spirit level should be 
used on the upper edge of the ring during each drawing to insure a 
straight and even casting. This process of ramming and drawing the 
ring is continued until the top of the ring comes in line with the gauge 
mark or line on the stake representing the under side of the cores D 
used to form the middle flange and trunnions. 

At this point, when the outside has been rammed, a level bed or 
seat is struck off at the top of the ring, the ring drawn up as before 
and the cores D set on top of the bed and in contact with the ring. 
These cores should be pasted together before being placed in the mold. 
After the cores D are in position the ramming and drawing is con- 
tinued until the under side of the upper flange cores C is reached, 
as indicated by the mark on the stake at the distance A from its top. 
The ring is then drawn to the level of the bottom of these cores and a 
bed struck off at this point to ue used for setting the cores C. 



34-V 



REPRESENTATIVE PATTERNS 



After the cores C are in place the ring is drawn up so that its 
upper surface is level with the top of the required casting and a joint 
or bed struck off for setting the covering cores E. The ring is then 
drawn several inches higher, and the inside of the mold rammed up as 
shown. The ring and vent sticks are then drawn out, and the covering 
cores E, placed in position on top of the cores C, care having been 




SECTION A-A 
Fig. 48. Casting for Strainer Tank 



-A— 



taken first to file or cut the necessary gates in the cores E. A runner 
is formed on top of the cores E as shown, and weights placed over the 
outer portion of the cores E to hold them in position. The necessary 
pouring basin is then formed in connection with the runner on top of 
the cores E, when the mold will be ready to cast. 



CYLINDRICAL CASTINGS 



35-V 



The core box for forming the cores D is shown in Fig. 47, and a 
similar core box without the trunnion pattern is used for forming the 
cores C. 

During this work care must be taken to see that the sticks for 
forming the vents are drawn up at each ramming as, if they are left in 
the mold too long, considerable difficulty will be experienced in draw- 
ing them. On account of the fact that comparatively thin courses are 
rammed at a time, that is, from 4 to 5 inches, it is not necessary to have 
the ring pattern over 6 or 7 inches wide, and in most cases, any 




Fig. 49. Sweeping the Bed 



additional width beyond this is entirely unnecessary, as it only adds 
to the difficulty of drawing the pattern if too great a width of it be 
rammed up at one time. In case no ring pattern is in stock, it would 
be necessary for the patternmaker to build up a ring of segments, turn 
up a wooden pattern with the necessary finish on all faces and have a 
casting made from which the iron ring pattern can be turned up in 
the machine shop. 

A somewhat more intricate casting of the above mentioned type 



36-\- 



REPRESEXTATIl 'E PAl'TERXS 



is shown in Fig. 48. It will be noticed that this has an internal 
bottom flange, four cast feet, an external top flange, and a pair of 
ears. The casting is to be used as a filter, or strainer tank. 

The method of proceeding with the work is shown in Figs. 49 
and 50. It is first necessary to strike off a level bed and in the center 
of it drive a stake containing the dowel pin C, Fig. 49. To this dowel 
pin is attached the sweep B, the striking edge of which contains the 
form of the under-side of the feet. By revolving the sweep about 
the stake a bed is struck off as shown. The dowel pin C is then re- 
moved from the top of the stake and right-angle lines are drawn 




Fig. 50. Section of Mold 



from the center of the stake across the bed to locate the four cores 
D, which arc made in halves and pasted together. These cores are 
placed in their correct position against the swept surface of the bed. 
To prevent the weight of the cast iron ring pattern from being born 
entirely by the foot cores D, four pieces of bar or rod iron are 
driven into the bed as indicated at E. These rods, however, should 
be placed half way between the cores D. 

The sweep stake is now removed, and in its place is firmly driven 
the long stake as shown by the dotted lines, Fig. 49, and the full lines 



CYLINDRICAL CASTINGS 37-V 

in Fig. 50. This stake extends up to the level of the under-side of 
the top flange of the casting. As in the previous example, the distance 
F is marked ofif on the stake to locate the under side of the cores H, 
which serve to form the lifting ears. The cast iron ring jM, of the 
required inside and outside diameter and having a face of about 8 
inches, is placed in position, being supported by the rods E and the 
cores D. They should be tested with the spirit level. 

As in the previous example a number of one-inch pins about 16 
inches long should be driven down into the bed at various points to 
form vents. The first section of the flask is then placed into position 
and staked down as shown in Fig. 50, after which the operation of 
ramming is proceeded with. The outside is rammed first to the 
height of 2 or 3 inches above the lower edge of the ring, care being 
taken to see that the ring is not rammed out of place. 

Any sand that may have been rammed under the ring and into 
the inside of the mold is then removed, and the cores G, which form 
the internal flange at the bottom are set into position, and the rods N 
are driven into the bed back of them. The inside and outside are 
then rammed up to the height of 5 or 6 inches, a vent wire being used 
between the vent sticks. The ring and vent sticks are then drawn up 
several inches, the operation of ramming and vented repeated, care 
being taken to see that the green sand core is well rodded. 

The spirit level should be used on the upper edge of the ring 
during each drawing operation to insure a straight and even casting. 
The process of ramming and drawing the ring and vent sticks is 
continued until the top of the ring comes in line with the gage line 
marked on the stake representing the under-side ear cores H. At 
this point the outside is rammed up and a level bed struck ofif at the 
top of the ring as shown in the dotted lines. Fig. 50. The ring is 
then drawn up in line with the top of the stake, the ear cores H set 
in position against the ring and diametrically against each other. The 
operations of ramming, venting and drawing the rods, together with 
the introduction of the iron rods necessary for supporting the core 
are continued to the top of the ring and cores H, at which point the 
bed is struck off to receive the flange core J. These are then set in 
place and backed up with sand to the top of the flask, as shown in Fig. 
50. The forming of the pouring basin and risers and the weighing of 
the cores J, completes the mold. 

The core boxes for forming the four dififerent cores are shown 
in Figs. 51, 52, 53 and 54. Fig. 51 shows the box used in forming 
one-half the foot core, an opposite hand piece ^1 being required in the 
box to form the other half of core. Fig. 52 shows the box for forming 



38-V 



REPRESENTATIJ'E PATTERNS 



one half the Hfting ear core, which also requires an opposite hand 
piece N for the other half. Figs. 53 and 54 show the frames employed 
in forming the upper tiange core J and the lower internal flange core G. 
The ring casting can be made with the aid of a segment pattern attached 
to a stake, and subsequently turned to dimensions. 




Fig. 51 




Fig. 52 




Fig. 54 



Fig. 51. Core Box for Feet. Fig. 52. Core Box for Lifting Ears 
Fig. 53. Core Box for Upper Flange Core. Fig. 54. Core Box for Internal Flange Core 



A NOZZLE PATTERN 39-V 

CHAPTER VII 

SKELETON PATTERNS 

As the building of a complete pattern for large irregular cast- 
ings such as nozzles, saddles, etc., is not always practical, the form of 
pattern commonly known as skeleton or frame pattern is resorted to. 




Fig, 55. Cast Steel Nozzle 

This practically consists in the construction of a skeleton or frame, 
the interior and exterior form and the thickness of which correspond 
to the required casting. The pattern work can be made more or less 
elaborate, according to the manner in which the molder desires to 
proceed in the construction of the mold, and upon the ability of this 



AO-Y 



REPRESENTATIVE PATTERNS 



individual tlie evenness of the casting to a great extent depends, as the 
skeleton gives an outline only and a partial guide for the strikes. 

Three views of one section of a cast steel nozzle weighing about 
19,000 pounds are shown in Fig. 55, two of these castings being bolted 
together at A and subsequently riveted to the shell. While there may 
be several ways in which a skeleton pattern for a casting of this de- 
scription may be constructed, the one under discussion has proved 
very satisfactory. 

The completed skeleton is shown in the reverse position to that 
in which it is built and cast in Fig. 56. The contraction of steel cast- 




Fig-. 56. Skeleton Nozzle PattiTn 



ings of this description and size is uncertain, and in most cases they 
will not contract, the usual allowance of 3-16 per foot, hence, an allow- 
ance of % of an inch per foot, with an extra allowance for finish for 
exact dimensions will eenerallv be found sufficient. 



Construction of the Skeleton 

Following the general practice of laying out the required full size 
sections, the building of the concave tlange B is the first part of the 
work to be undertaken. To facilitate this operation, a form can be 
lagged up as shown in Fig. 57, conforming to the concave surface of 
the flange and upon which the flange is laid out and built, one quarter 
at a time. The segments for the flange are fitted, dressed to thickness 



A NOZZLE PATTERN 



41-V 



separately and then tongued together as shown. A number of forms 
as shown in Fig. 58 are next gotten out and Uned and leveled up on the 
floor, taking care to see that they are securely braced. The four 
quarters of the flange B are located and fitted together over these forms 
and secured to one another. 

To facilitate the handling and storing of the pattern, if desired a 
joint can be made on the lines C C, Fig. 55. and the two halves 
screwed together. 

The ring D. Fig. 56. forming a part of the skeleton and to which 
the ribs are secured is built up of segments turned to size and then 




Fig. 57. Form for Base Flangre 

elevated and secured with suitable supports and braces in its proper 
relation to flange B. 

It is next necessary to space off and locate the ribs. To facilitate 
the cutting out of the ribs, material about Js of an inch thick can be 
used, each piece being fitted in place and gotten out as a templet antl 
later when the templets have been dressed to form they are reinforced 
on both sides for strength and replaced in position as ribs. This 
method results in a saving, both of material and time. 

As the only sections shown by the draftsman are those illustrated 
in Fig. 55, it becomes necessary without developing the section at 
each rib, to work from one section to another. The templets for one- 
half of each end are gotten out with the outer edges, sawed roughly to 
form. They are then placed in position and temporarily secured, when 



42- V 



REPRESENTATIVE PATTERNS 



with the aid of a flexible strip and the eye the outer edge of each tem- 
plet is dressed to form, working from one section to the other. The 
templets for the opposite half of the end are now marked from those 
already made and tried in place. The templets are then reinforced for 
the proper thickness, after which the metal thickness or interior form 
of the skeleton is laid off on each rib and they are dressed to the proper 
thickness. They are then returned to place and secured in position. 
It will be observed that no. provision is made on the skeleton for the 
flange E, Fig. 55, this flange being made up during the molding opera- 
tion by using a segment. 




Fig. 58. Form to Support Pattern 



Making the Mold 

A hole is first dug in the floor to the required depth and two 
of the forms shown in Fig. 58 which were used for supporting the 
skeleton while it was being built are used for striking up a bed upon 



COVERING CORE 




Fig. 59. Section of Nozzle Mold 

which the skeleton may rest. The forms are then removed and the 
skeleton set in position upon the bed. The core is then rammed up. 
To facilitate this operation and to prevent the sand from ramming out 
through the openings, boards can be set up to the openings and 
braced from the walls of the pit. 

The gates are arranged as shown in Fig. 59, and the runner pre- 
pared as the ramming progresses. After the core has been rammed 
up the boards surrounding it are removed and the core or body of 
sand dressed and slicked to the shape of the outside of the skeleton. 
The exact form and evenness of surface will depend to a large extent 



A NOZZLE PATTERN 



43-V 



upoji the molder's ability and judgment. The cope or cheek is then 
rammed up upon tJiis outer surface. In order to do this, the parting 
is prepared, the flask placed in position and rammed up in the ordinary 
manner. The depression forming the upper flange E being made with 




the aid of a segment representing a section of the flange and at the 
same time a seat for the covering cores is swept off on each side of the 
segment. The cope or cheek is now lifted off, blocked up and finished 
in the usual manner. 



44-V 



REPRESENT ATI]- E PATTERNS 



The sand between the ribs of the skeleton which represents the 
metal thickness of the casting is now removed from the core and the 
skeleton lifted off. The accompanying half tone, Fig. 60, shows a 




Fig. 61. Double Nozzle Casting 



view of the mold at this stage. The core is now dressed to form, after 
which it is dried. The various parts of the mold are next assembled, 
the cope or cheek lowered into place, the covering cores to form the 




Fig. 62. Skeleton Pattern for a Double Nozzle 

upper face of the flange E set, and risers prepared, and the space be- 
tween the walls of the pit and the flask firmly rammed with sand. The 
mold is then weighted down ready for pouring. A cross section of 
the complete mold is shown in Fig. 59. 



A NOZZLE PATTERN 



45-V 



A Double Nozzle Pattern 

Three views of a steel casting for a double nozzle as shown in 
Fig. 61. This differs considerably from the one already shown and 
brings out some different principles in molding. A plan of the 
nozzle is shown in the upper right hand corner. A section on the 
line A-A, is shown at the left, and a section on the line B-B at the 
bottom. The pattern is parted upon the line B-B. A view of the 
completed pattern in the position in which it is built is shown in Fig. 62. 

In building the pattern the required sections are first laid out full 
size. The building of this skeleton is similar to the pattern already de- 
scribed. The lower flange G is gotten out and built up over a form. 
The two upper flanges H-H are built up and turned with the lower half 
left loose, so that these two half flanges may be drawn separately. 
The rings I are secured by supports and braces in their proper relation- 
ship to the flange G, after which the ribbing of the skeleton is pro- 




Fig. 63. Section of Mold for Double Nozzle 

ceeded with. To assist in getting out the ribs forming the parting of 
the skeleton, a form ma}' be lagged up corresponding to the parting, 
the outline of the rib laid out upon this convex surface and the rib built 
up in segments. After one rib has been built in this way, the one 
on the opposite side of the parting may be made to fit it. The location 
and building of the other ribs is similar to that already described. 

Making the Mold 

The molding of this skeleton differs from the one previously de- 
scribed in as much as it is cast upon its side, and with the aid of a 
core bar the core or inside is lifted out. This necessitates the prepara- 



46-V REPRESENTATIVE PATTERNS 

tion of a seat for locating and supporting the core when it is returned 
to the mold. A hole is first dug to the required depth and the drag 
half of the pattern is bedded in to the thickness of the ribs. The inside 
is then slicked and dressed to form and the seat for the core prepared 
as shown in the cross section of the mold, Fig. 63. 

The core bar is next placed in position and the drag half of the 
core rammed up. The parting outside of the skeleton is prepared 
and the cope half of the skeleton placed in position , after which the 
ramming of the interior is proceeded with. 

Owing to the angle on which the flanges are set, the faces of 
the flanges from the parting line down are formed by the core as shown 
in the cross section of the mold in Fig. 63. In other words, as far as 
this portion of the flange is concerned, the core forms an intermediate 
part for the mold. When the core is lifted out, the lower portion of the 
flanges are exposed and left free to be drawn. 

When the ramming of the upper half of the core for the interior 
of the skeleton is completed, this portion of the skeleton is lifted off 
and the core slicked and dressed and paper applied, after which the 
skeleton is returned and the openings between the skeleton filled with 
sand and slicked off so that it will form a body upon which the cope 
is rammed in the usual manner. When the cope is completed, it is 
lifted off, together with the cope half of the skeleton. The cope is 
then blocked up, the sand between the ribs removed and the half of the 
skeleton pattern drawn. 

With the aid of the core bar, the core is then lifted out, blocked 
up, and the sand between the ribs of the lower or drag half of the 
skeleton removed and the skeleton lifted out. The drag portion of 
the mold is then finished, the runner and risers are prepared during 
the ramming up of the mold. The mold and the core are then dried 
assembled, and prepared for pouring in the usual manner. 



A CHILIAN MILL MORTAR 
CHAPTER VIII 



47-V 



PATTERN FOR A CHILIAN MILL MORTAR 

Several views and sections of the casting to be made are shown 
in Figs. 64, 65, 66, 67 and 68. In Fig. 64 there is given a half plan 
and sectional plan on the line AAA, Fig. 67, which shows the upright 
members of the casting located between the screen openings, together 
with the wedge chucks B and C. These wedge chucks are used for 
wedging or securing the screens in place. Fig. 65 shows the bottom 




SECTION AT A-A-A 
Fig. 64. Plan of Chilian Mill Mortar 

or inverted plan of the mortar, while Fig. 66 gives a side elevation, 
and Fig. 67 a longitudinal section of the mortar taken on the center 
line DD, Figs. 64 and 65. This section, with the radial sections shown 
in Fig. 68, which are taken on the lines EE, FF and GG, Fig. 64, 
should receive careful attention in order that the construction and 
molding of the pattern may be more readily understood. It is from 



i8-V 



REPRESENTATIVE PATTERNS 



these four sections that the pitch of the trough is obtained and the 
laying out of which will be described during the construction of the 
pattern. 

Of course a full size working lay-out is essential for reasons well- 
known. The sectional lay-out should be taken through the center of 
the mortar as shown in Vig. 67, and this view will also serve for laying 
out the trough, etc. A lay-out of the plan is also required, but as the 
mortar is symmetrical about the center line DD, Fig. 64, a half plan 
lay-out is all that is required. 




Fig-. 65. Bottom of Mortar 



Construction of the Pattern 

While a mortar pattern of the design shown is not of a particularly 
intricate nature it nevertheless contains some very good features in 
patternmaking and also in molding. The writer has made a number of 
mortar patterns of this general type in the manner described and this 
method of constructing the pattern as shown has been found to give 
a durable pattern and at the same time is as economical in time and 
material as could be desired. 



A CHILIAN MILL MORTAR 



49-V 



The upper view in Fig. 69 shows a longitudinal section of the 
assembled pattern taken on the center line DD, Fig. 64. This section 
should give a fairly good idea as to how and where the various parts 
of the pattern are joined and fitted together. While all of the partings 



Trough 




Fig. 66. Side Elevation of Mortar 



shown are not essential or required in molding they nevertheless facil- 
itate the drawing and also tend to prolong the life of the pattern, on 
account of the fact that the different parts can be removed from the 
sand separately and with less rapping as the dressing of the mold pro- 
ceeds. 




SECT/ON D-D 
Fig. 67. Longitudinal Sectioh of Mortar 



Another advantage in constructing the pattern in sections is that 
it is easier to handle and store. This sectional construction also affords 
protection to the hopper sections, \\hich is of rather light and frail 
construction. 

Shown at the left in the upper view of Fig. 69 can be seen one 
of the wedge chucks B. By studying a section of one of these chucks 
as shown in Fig. 64 it will be seen tliat it v.'ould be necessary to core 
out the slots and if this were done with a dry sand core it would neces- 



50-V REPRESEXTATirE PATTERNS 

sitate a troublesome core setting, as it would come on the parting line 
of the drag and cheek portions of the mold. To avoid this objection- 
able feature this part of the pattern was arranged as shown by a section 
of the chuck at the upper left hand corner of Fig. 69. This has over- 
come the difficulty very satisfactorily, as the arrangement allows the 
two ears to be drawn in and the dry sand core set in place to form 
the outline of the back of the chuck as indicated by the dotted lines. 
Wedge chuck C is shown to the right in the figure and the manner of 
coring out the slot is self-explanatory. 

Shown at the bottom of Fig. 69 are the four separate sections 
or parts that form the body or center of the pattern, arranged in the 
order in which they are placed together. In beginning the building 
and turning up of the parts the center portion H receives attention 
first. This part can be built up on the face plate of the lathe some- 
what after the manner and in the position shown. This is followed 
by the turning of the face, wi'ih its two offsets I and J. Offset I 



SECTIONS E-E F-F C-G 

Fig. 68. Sections of Rim of Mortar 



receives and locates the lower rail K of the hopper, while offset J 
locates the center or conical portion L of the pattern. 

The most convenient manner of disposing of the two parts K 
and L is to build them up and turn them in position upon part H, as 
shown bv the dotted lines. It will be seen that all that is necessary is 
to fit the first course of segments in their respective offsets, pin and 
screw them in place, taking care to leave the heads of the screws 
exposed so that they may be removed and then proceed with the 
building up and turn in in the usual manner. 

At the completion of the two members they are removed and part 
H rechucked so that it can be turned on the outer diameter and back. 
During this turning the offset M'is formed to receive the core print 
N, as shown. The hub O is of course turned independently and fitted 
in place during the turning of the portion L. 

Our attention is next given to the upper rail O of the hopper 
which is built up and turned as shown. 

The center lines and widths of the five standards P are next 



A CHILIAN MILL MORTAR 



51-V 



laid off on both rails K and O, the rails are then cut out to receive 
the standards and the latter portions secured in place as shown. After 
fitting on of the wedge chucks B and C, the building up of the trough 
which is shown in plan and section in Fig. 70 next takes our attention. 




Loose Dowels 

Joint in Pat 



CROSS SECTION OF ASSEMBLED PATTERN 




HALF ELEVATION 



HALF SECTION 




HALF SIDE ELEVATION HALF SECTION 

Fig. 69. Details of Construction of the Pattern 



This figure shows a half plan and longitudinal section through the 
center on the line DD, also radial sections on the lines EE, FF and GG. 
These latter sections serve to illustrate the general construction of the 
pattern. By studying the figure it will be observed that the pitch of 



52-V 



REPRESENTATIVE PATTERNS 



the trough is not regular, as is the usual practice in the designing of 
mortars of this type, that is, it does not have a uniform pitch or drop 
from back to front, which would, of course, bring the bottom of the 
trough always in the same plane. In the case under discussion the 




Fig. 70. Construction of the Trougrh 



pitch of the trough varies, the amount of pitch or drop being given 
at four stations, S, T, U and V, at the center of the trough, as shown 
by the radius X, the pitch being decreased toward the apron. 



A CHILIAN MILL MORTAR 



53-V 



In the lower part of Fig. 70 Is shown one way in which the trough 
may be laid off and built in position up to the body portion of the 
pattern. This manner of constructing the trough will be found about 
as convenient as any other method. The five stringers, AA, BB, CC, 
etc., representing the five stations of the drop or pitch of the trough, 
are first gotten out and dressed to the required height of the under- 
side of the trough as shown. They are next secured to the work table 
in their respective positions and-their proper relationship one to another 
and also to the body of the pattern, which is placed in position and 
secured temporarily as shown. 




SECTION J.J 
Fig. 71. Core Box 



The segments or material FF, which is to form the bottom of 
the trough are next gotten out roughly to size and of ample thickness 
and width to allow for sawing and dressing to form. In length the 
material FF is gotten out equal to the distance between stations, at 
which points it is butted together as in segment work and temporarily 
bradded down. 

Next, with the trammels so arranged that one point will extend 
down over the center portion, H into the center of the trough, the 



54-V REPRESENTATIVE PATTERNS 

center line of the trough or the radius X is scribed. The dififerent 
widths at the bottom of the trough are now taken from their respective 
layouts as shown in the upper ])art "of Fig. 70 and transferred to the 
material as shown at AA, BB, CC, etc. This is followed by the sawing 
of the segments to size. 

The next work consists in the dressing ofif of the underside of the 
segments from station to station so that the segments will conform to 
the pitch. This is done carefully by the eye, and the exercise of a little 
judgment is all that is necessary, as there is nothing of great impor- 
tance attached to the trough and a slight variation one way or the 
other will not make any material difference. 

Having the underside of the material or segments worked to form, 
it is next necessary to reduce them to the required thickness, which 
is a verv simple operation. After this the segments are returned 
and bradded in place. The lower part of Fig. 70 shows the work at 
this stage of completion, ready to secure the segments, the positions of 
which are indicated by the dotted lines. The first course of segments 
at the inner and outer diameters of the trough must be applied to the 
irregular surface, hence it will be necessary to chalk and fit them for 
a glued joint. 

After these two courses are fitted and glued in position their upper 
faces can be joined straight, which will allow the remaining course 
to be joined in the usual manner. If each co.urse of segments is care- 
fully marked from the previous course, applied and sawed to line and 
beveled, very little work will be required in dressing them to form. 

As the first course applied forms the fillet, it will be necessary 
to work this out with a gouge. It will be noticed that the first two 
courses of segments which form the inner wall of the trough are fitted 
up to part H of the pattern for about half of the distance around 
the pattern from which point they extend or flair outward on to the 
apron, as shown. 

Before removing the work previous to dressing up the under sur- 
faces holes should be bored for loose dowel pins to attach the trough 
to the body of the pattern to facilitate the process of molding. 

Next, the usual provisions for rapping and drawing the various 
parts of the pattern must be made, the pattern finished with shellac, 
etc., when our attention will be given to the construction of the core 
box. 

The core box necessary is shown in Fig. 71. The core made in 
this box forms the interior of the conical center of the casting, as 



A CHILIAN MILL MORTAR 



55-V 



shown in the cross section of the completed mold, Fig. 72. The illus- 
tration of the box shows its construction fully so that no detailed 
description is necessary. 

Molding 

The manner of making the mold is clearly illustrated in Fig. 72. 
As this section is taken at the center line of the mold the parting 
appears about on a line with the joint of the flask. This fact would 
not be the case at the right or left of the section shown, owing to 
the pitch of the trough to the right and left of the line, upon which the 



E 





r 


^^ 


'^^i.v 


til 


■I'l^ 










f('l>r 






'; Vi^u- Jr 


-r ^ 

/ 


. K K 


a 


^ V 




■ 




flicrk : 








\- . 


^ , 



Fig. 72. Section of Mold for Mortar 



section was taken. The parting would, of course, extend up into the 
cope on one side and down into the cheek on the other. By inverting 
the upper view in Fig. 69 the line of the parting can be easily followed. 
In drawing the pattern from the sand the cope is lifted off first, 
the trough portion of the pattern drawn out, and this permits the lifting 
off of the cheek. The line of parting between the cheek and the interior 
body of sand which forms the interior of the hopper is shown along the 
lines KK. After the cheek has been removed the other sections of 
the pattern can be withdrawn in their respective order and the mold 
finished in the usual manner. 



56- V REPRESENTATIVE PATTERNS 

CHAPTER IX 

THE MAKING OF A CROOKED ELBOW 

Life is made interesting for the patternmaker at times by the 
various problems, meehanical, geometrical and otherwise, which are 
presented to him for solution in the course of his daily duties. The 
making of the elbow described in this Chapter presents a few of these. 

This elbow was made to connect with a rectangular pipe 6x9 
inches, which passed around a cylindrical body with a fiat, conical head 
having an opening 7 inches in diameter. Metal thickness was specified 
as 3-16 inch, but the patternmaker and the molder between them prob- 
abl\' increased this a little by the process known as playing safe. The 
variation, however, was not more than 1-16 of an inch, as weight was 
an important item. 

In producing a pattern of this character, or, in fact, in producing 
anv pattern, the first consideration with the practical patternmaker is 
the manner of molding it. Notwithstanding the opinion of our friends, 
the molders, to the contrary, a goodly number of patternmakers are 
wearing gray hairs (when they are not bald headed) from worrying 
over this very question of the moldability (to use a newly coined word) 
of patterns. 

The elbow is shown as projected in the three views at the left of 
Fig. 72) and the first thing to determine is just where or how to mark 
the parting line in order to avoid waste of lumber in gluing up the 
necessary block from which to make the pattern. The first piece should 
be large enough to include all of the curved part of the pattern, the end 
flanges and core prints being made separate, and as these latter are of 
known shape and dimensions they are an easy proposition, and when 
finished can be screwed to the main portion of the pattern. Lines A 
and B, while not a true projection, will give the average patternmaker 
a better idea of the method of parting this pattern than the projection 
lines would. 

The material being glued up for the several parts, the part for 
the drag or lower half of the pattern is then cut to conform to the 
parting line. To aid in this work free use should be made of the sur- 
face table if you are fortunate enough to possess one, or a trued-up 
board can be made to answer if no surface table is at hand. This 
will result in a saving of both time and lumber, especially if the pattern- 
maker can secure a surface gauge of sufficient size from his friend, 
the machinist, for it is not likely that one will be found in the pattern 



58-V REPRESENTATIVE PATTERNS 

shop equipment, though it should be there. By clamping the base of 
the surface gauge to the table, it is easy to turn it into a sliding tram- 
mel which can be raised or lowered at will and still keep the same 
radii, the stem being set up perpendicular to the face of the board. 
This makes it easy to lay out many lines, even on a rough surface, and 
to do it in shorter time than can be done by projection. It is also 
accurate. 

You will notice that the parting line has to be twisted at the round 
end of the ijattcrn in order to make it possible to place the core into 
the mold in one piece and also to produce a pattern with as few loose 
pieces as possible. It will be found easier to make this part from the 
bottom of the slope (line C, Fig. 72)), separate and then set it to the 
correct angle and screw it in position, after which the bevel from this 
to the main line of parting can be worked out. This being done, the 
upper or cope half of the pattern is then fitted to the lower half, form- 
ing a complete joint, and the two doweled together. Xext, the form 
of the pattern is laid out on the joint and the two parts are finished 
together. In this work we must again depend upon the surface plate 
to make sure that there is no back draft, care being taken to place the 
pattern in exactly the same position each time it has to be removed from 
the surface plate. 

It is necessary that the flanges be loose from the body of the 
pattern, on accovmt of the angle at which they are placed and the curve 
that fits the cone. Otherwise it will not be possible to draw the pat- 
tern. These loose pieces should be placed in a groove, in order to 
insure their staying in position while ramming and also to give them 
strength. The portion of the upper part of the pattern marked "loose 
piece" should also be doweled on separately, as the angle of the end 
is such as to prevent a straight draw. 

In making the core box, the block for the lower half of which 
is shown embedded in the sand, it is first necessary to make the block, 
which is composed of three pieces for the body and two pieces to close 
up the ends. These are screwed together and fitted at the joint to the 
upper half of the pattern. This done the construction lines 1-1, 2-2, 
Z-2>, etc., are marked on the pattern and transferred to the joint of the 
core box. The outline of the pattern is also marked by a scratch awl 
while it is lying in position upon the core box. Another line is then 
made inside of this corresponding to the thickness of the metal. 

Templets are next made of thin pieces of wood and fitted to the 
pattern at the lines marked, and at as many additional places as the 
patternmaker thinks necessary. From these other templets are made 
for the core box, allowing the thickness of the metal between them, 



A CROOKED ELBOW 59-V 

as shown in the upper right hand corner of Fig. 7Z, which illustrates 
the templet for line 6-6 of the drag half of the pattern. 

Before we proceed to cut out the core box, it is necessary that we 
provide for the requisite core plates upon which to dry the core and 
it is highly important that these be true to shape, as otherwise the 
cores will not joint up and the results will be either too thick metal or 
a defective casting from the cores cutting through where they should 
not. As a simple method to insure the shape of these plates the writer 
uses the block prepared for the core box as a follow board, as indicated 
in the lower left hand corner of Fig. 7Z. Upon this were fitted two 
pieces, say ^ inch to one inch wide, as an outline for the core plates, 
these pieces being 5-16 inch thick. Between them sand was filled in and 
swept off to the required thickness. This sand was then freely 
sprinkled with parting sand and upon it placed ribs, as indicated. 
These ribs are intended to bring the plate to a level bearing and also to 
strengthen it and prevent its losing its shape from the heat of the core 
oven. A flask was then placed over this and molded in the usual 
manner, first ramming up and placing the bottom board, then rolling 
over and making the cope half after lifting off the frame. The strips 
are then removed and the sand lying between them removed, the ribs 
drawn, and, except for the connecting gates, etc., we will have the 
mold for the core plate for the lower core. The same method is used 
for molding the core plate for the upper half. 

We next proceed to cut out the core box, using the templets for 
this purpose, put in the finishing touches, varnish, etc., when the job 
is completed. 



SECTION VI 



HINTS, SUGGESTIONS AND RIGS 

CHAPTER I 
CUTTING THE SCORE IN A CHAIN DRUM PATTERN 

Frequently when a number of drums are required, the casting of 
scored chain drums, as shown in Fig. 1, is resorted to; and when of 
too small a diameter to sweep conveniently, a complete pattern is re- 
quired, parted longitudinally through the center and molded likewise. 
In some cases, particularly that of a coarse pitch, which requires the 
pattern to be partially revolved while being drawn from the mold, as 




6 


> 


1 '^ 


4 
3 

1 

Y 


1 


1 ,' 




, • . , 


»4 


23 


/ , 1" 


1 -' 




I I ■ 






FiK.2 



Fig. I. Chain Drum. Fig. 2. Pattern for Chain Drum 

the revolving of the pattern will cause it to travel forward in the mold, 
a detachable core print may be placed at one end of the pattern, leaving 
a depression into which the pattern may protrude while being drawn. 
The barrel having been staved up in the ordinary manner, of ma- 
terial of sufficient thickness to permit the cutting of score, it is placed 
in the lathe and turned to the required outside diameter and the center 
line of score marked ofif before removing it from the lathe centers, as 
shown in Fig. 2. 



2-VI 



SUGGESTIONS AND RIGS 



One way in which the laying off of this center Une can be easily 
accomplished is to locate the starting point of the score Y, and scribe 
a line around the barrel as shown by XX, Fig. 2. Now from starting 
point Y step off the circumference into any number of equal points, 
and through these points draw longitudinal lines from end to end of 
the barrel as shown. 

The lead or pitch of the score or the lead or pitch of any screw 
is the distance it would travel forward in one revolution. Hence, if 
the circumference of the barrel be developed as shown by V, Fig. 3, 
and a perpendicular line W be erected at one extremity, in height the 
equivalent of lead or pitch of score, the line Z or the hypotenuse of 
the right-angle triangle thus formed will be the angle of center line 
of score about the barrel. 



.11 I I I I' 



3 4 5 7 » 9 10 11 1^ 13 14 11 l'.; 17 la n 20 -n •:L S.UJplT^h^f 
^V Cincumferenue ot Barrel — >1 Bcore 




SECTION A-A 
Fls.4 



[?_ 



.S.PJNDLE 



rig,6 



Fig. 3. Development of Score. Fig. 4. Cutter Head. Fig. 6. Cutter Spindle 



Now if the developed circumference V be divided into the same 
number of equal parts as the barrel, 1, 2, 3, 4, etc., the transferring of 
this center line Z to the barrel becomes a simple operation, for by using 
the line X scribed around the barrel at the starting point of score, Y, 
Fig. 2, as the base line, V, of the developed circumference, Fig. 3, 
with the dividers, transfer the distances 1, 2, 3, 4, etc., to the corre- 
sponding longitudinal lines on the barrel. Then with a flexible rule 
or strip connect these points, which will give the center line of the 
score for one revolution, the continuation of which is very simple. 

As a right or left-hand thread is confusing to some, a good point 
to bear in mind is that a right-hand thread raises to the right and a 
left-hand thread raises to the left ; or to observe the thread of an ordi- 
nary wood screw, which is invariably a right-hand thread. If the 
score is to be cut by hand, lav out the width of score from center line 



CUTTING THE SCORE IN A DRUM 



3-VI 



and proceed with back saw-gouge and templet. Any workman who 
has worked out the scoring on a drum by this method has no doubt 
found it a slow and tedious job. 

Illustrated in Fig. 5 is an arrangement of lathe with a cutter 
attached and the barrel so placed as to permit the cutting by power. 
While the initial cost of fitting up the cutter, etc., should not exceed 
six or seven dollars it would reduce the actual time of cutting to a 
minimum, and would do the work at a cost below that of cutting by 
hand a drum 30 inches in diameter and 54 inches long at SIjAc per 
hour. 




Fig. 5. Lathe Rigged to Cut Score 



The spindle and cutter are shown in greater detail in Figs. 4 and 
6, the cutter being turned to form and cut out as shown, and filed up 
to form a cutting edge. A good, substantial block, A, having been 
gotten out with slot cut out to receive guide E, and the top dressed 
ofif to a sufficient angle, B, to bring the cutter in line or in the same 
plane as that of the score of drum. The bracket C is now attached 
and this arrangement secured to the lathe bed as shown, and in line 
with a pulley, D, previously turned upon face plate. The center line 
of score having been layed off on the barrel as previously described, 
a portion of the score long enough to take in the cutter and guide E 



4-VI 



SUGGESTIONS AND RIGS 



is cut out by hand to exact templet. The shaft or spindle F, which 
will be governed by what can be found around the machine shop or 
the spindle used in the foundry, should be twice the length of the 
barrel plus the width of supports G. The barrel-heads having been 
cut out to receive the spindle, the barrel is placed upon the spindle, 
set upon supports G and clamped down. 

The barrel is now placed in position with the portion of the com- 
pleted score opposite the cutter, which is now moved forward to its 
correct position and secured, as is also the guide E, which must fit 
the completed score snugly. The cutter, revolving in the direction 





Fig. 7. Cutter on Back of Spindle 



Fig. 8. End Mill Type of Cutter 



indicated by arrow, is now set in motion, the barrel revolving toward 
the cutter and upon spindle F, guide E, following the cut score, giving 
the lead and forcing the barrel along the spindle. 

To lessen the friction of the barrel and spindle a roller can be 
adjusted underneath the barrel if necessary. Also, pieces can be 
screwed to the end of the barrel to facilitate revolving. If the score 
is very deep, a portion of the material may be removed and the score 
completed with a second cut. 

There is another way of getting out this work and it differs in 
several respects from the one already described. The principal varia- 
tions from the other plan are in the location of the barrel — which is 
in a transverse position — and in the cutter which is of an entirely 
different shape and is shown attached to the lathe spindle in Fig. 7. 
The setting and handling of the barrel during the cutting operations 
remain identical with the former arrangement. 

The cutter is seen in greater detail in Fig. 8 and may be attached 
to the lathe spindle as illustrated or it can be provided with a taper 
shank to fit the center of the spindle. The cutter having been turned 
to the required form and fitting the spindle, the sides A are milled off 



CUTTING THE SCORE IN A DRUM 5-VI 

and the material at B removed by drilling — leaving the wall C of 
about 5-32 of an inch in thickness. The cutter edges are then filed up, 
tempered and whetted to a freely cutting condition. To overcome 
the plain blunt surface D at the extreme point of the cutter and which 
would not remove the stock, a small slot E is filed in it and this will 
be found sufficient to remove any possibility of trouble. 



6-VI 



SUGGESTIONS AND RIGS 
CHAPTER II 



A CORE BOX AND CLAMP COMBINED 

A combined core box and clamp, which will be found convenient 
and a time-saver where a number of cores are to be made, is shown 
in Fig. 9. While the illustration may be self-explanatory, a few re- 
marks will not be out of order. The central figure shows the plan 
of an assembled rectangular core-frame, or box, with clamp in place. 
To the left is shown the end view and the arrangement of wedges. A, 




Fig. 9. Combined Core Box and Clamp 

which are attached to the sides of frame, while the side view of box 
is shown at the bottom. At the top and right is shown the bottom 
board B. with clamp C attached, also stop D for locating the frame 
on the bottom board. 



LATHE TOOLS 



7-VI 



CHAPTER III 
SOME LATHE TOOLS 

A number of lathe tools which shops equipped with screw feed 
lathes are using, and which give very good results, are shown in 
Fig. 10. 

The roughing tool or gouge is shown at 1. The cutting edge 
should slant downward somewhat as it approaches the end or tail, 
to give a drawing cut, and the outside face ought to overhang at 
least 10 degrees from a perpendicular all the way around, so as to 
take hold nicely at the very edge, and not have any point of contact 
below where it is doing work, to retard its action. An emery wheel 




Fig. 10, Lathe Tools 



about 8 inches in diameter gives a good concave to the outer face, 
and when this tool has a few finishing touches with an oil stone, it 
is surprising to see the heavy chips it will take from a rough piece 
without even previously removing the corners. 

The ordinary flat tool which can be ground round or pointed, as 
indicated by the dotted lines, is shown at 2. 

A boring tool is shown at 3, and there should be one right and 
one left. I have used tools of this shape a great deal, and for deep 
boring know of nothing better. They also work equally well on out- 
side work and are especially useful when the piece being turned is 
too large in diameter to slide the carriage along under it, for it can 
be placed in the tool-post in such a manner as to overhang a long 
distance and work clear to its limit. 



8-VI SUGGESTIOXS AXD RIGS 

A nice tool for facing off segments and the surface of any disk 
which may be on the face-plate is shown at 4. It works quite well 
also when turning on the outside diameter, but is especially for facing. 

The tool shown at 5 is known as the "arrow point" tool and is 
used for finishing. It should be set slightly angling to the work. 
When properly sharpened it will cut almost as smooth as glass, and 
on straight work, like rolls, etc., it works as nearly perfect as one 
could wish. The action, it will be noticed, is similar to a wood- 
turner's skew chisel. 

A cutting-off tool, which does not tear and scrape like the ones 
generally used, that are flat on top, is illustrated at 6. It is intended 
to be sharpened on an emery wheel, about 6 or 8 inches in diameter, 
and then be touched up on an oil stone, as in fact are all of the tools 
described. The curvature on the upper side of this tool allows it to 
enter the work easily and take a fast cut, while the curve below re- 
moves the stubbed end frequently seen on tools of this class. One 
of these tools, made in every respect like No. 6, except with a wider 
cutting face, is excellent for shouldering down on work. With it 
a number of cuts can be made down to almost the diameter required, 
then get the exact diameter, and finish by moving the carriage along. 
The tools cut quite smoothly moved along in this manner, but not quite 
as well as the "arrow point." 

A boring tool which is useful in holes of small diameter where 
the one shown at 3 camiot be conveniently operated is shown at 7. 

A tool for general work, which is good for smoothing and 
shouldering down, is illustrated at 8. It will be noticed that it has 
two cutting edges which can be used, and the top is shaped by the 
curve of the emery wheel something as in No. 6. The angle of the 
point should be less than a right angle, as if so made the tool can be 
set so as to be started in with the slide rest, and then be stopped and 
moved along by the carriage. A much deeper chip can be taken with 
this tool when the carriage is moved than with the one shown in No. 6, 
as its action is more of a drawing cut. 

A handy lathe dog which will be found convenient while turning 
pieces in halves, avoiding the accustomed use of screws, is shown at 9. 



BALL TUR\UNG 

CHAPTER IV 

WOODEN BALL TURNING 



9-VI 



As patternmakers are frequently called upon to do work a little 
outside of their regular line, I feel that the following may be found 
useful to some. In turning a ball, first rough out as shown at the 
bottom of Fig. 11, forming two, three or more balls per stick, as size 
will permit. This turning should be done to within 1-16 of an inch 
of the finished diameter, using an ordinary sheet metal templet of the 
form shown in the upper right hand corner of Fig. 11. 



^Wood Chuck 




Fig. 11. Bolt Turning 



The balls are then sawed off and the unturned spots rounded over. 
A chuck should be turned and backed out as shown in the upper left 
hand corner of Fig. 11. This should receive the ball to within an 
eighth or a quarter of an inch of its center line. 

The ball is first placed in one position and the groove turned 
around the center line about an eighth of an inch wide and to the re- 
quired diameter, as shown in the illustration. The ball is then removed, 
given a quarter of a turn and a small groove turned at right angles to 
the first. All that now remains is to turn oft the surplus material be- 
tween quarters formed by the grooves. The ball is then returned to its 
original position and the other half finished. Chalking the inside of 
the chuck will assist in holding the ball in position. 



10-VI SUGGLSTIOXS AXD RIGS 

CHAPTER V 
SHRINKAGE 

All metals passinc: from the liquid to the solid state undergo ex- 
pansion when in the j)lastic condition. It is this feature in the transi- 
tion that enables the metal to take and retain the impressions of molds. 
In cooling from the plastic condition to the solid state most metals 
contract. The amount of this contraction in passing to a normal tem- 
perature will vary for the different kinds of metals. Patterns have 
therefore to be made larger than the desired casting by this amount. 
Here comes the necessity on the part of the patternmaker for the use 
of discreet judgment based upon extended experience in order to 
obtain the best possible results ; different mixtures of iron as well as 
alloys will contract varying amounts. Moreover, the varying propor- 
tions of the castings will vary in the amount of contraction. An 
extended and plain casting will contract dift'erently from one of more 
compact form, though both may be of equal weight and cast at the 
same time and of the same material. A heavy casting will contract 
less than a light one, while a small casting will often come out as 
large or even larger than the pattern. Hard metal will contract more 
than soft metal, and the presence of large dried cores in a mold will 
diminish or retard the contraction. A plain cylinder will contract less 
in diameter than in length. 

The contraction or shrink rule, as the name implies, is a rule that 
is made longer than the standard measure by the amount which the 
various metals will contract in cooling from the plastic to the solid 
state. Though a standard rule is required for the measurement of 
castings it would be obviously inconvenient to use it in patternmaking. 
The workman would be perpetually making allowances for contraction 
in fractional parts of an inch. So the shrinkage rule economizes his 
time and insures something more accurate than approximations. 

The conventional allowance for cast iron is 3-32 inch to the foot, 
but this rule needs modifications in its application as already discussed. 
Heavy bed plates, etc., are usually made with an allowance of 1-16 
inch per foot, and sometimes with the standard rule. The contraction 
of steel is quite uncertain, ofttimes varying from I/4 inch per foot to 
ys inch. However, the usual allowance is 3-16 inch per foot for 
ordinary work. ■* 



SHRINKAGE 



11-VI 



The common allowance made for the shrinkage of castings made 
of different metals is as follows : 



Cast Iron 3*, 

Steel J*: 

Brass T6 

Yellow Brass 3^2 

Bronze t^ 



inch per foot 




A method of graduating a shrink rule by hand — with the aid of 
a standard scale — is illustrated in Fig. 12, and when this is carefully 
done it will give entire satisfaction. Secure a standard rule to a board 
in such a manner that the upper surface will be clear. Erect the 
perpendicular line B C at one end. Now lay off the amount of shrink- 
age as indicated at D. With A as the center and with a radius equiv- 
alent to the length of the standard rule plus the amount of shrinkage 




Fig. 12. Making a Shrink Rule 

D, scribe an arc of a circle E F. Note the point of intersection with 
the perpendicular line B C which is shown at G. A strip of suitable 
material and of the same thickness as the standard rule is then secured 
to the board in the position shown, its inner edge passing through 
the point of intersection at G. The guide H can be made of steel 
plate or wood with the strip I attached to bear against the outer edge 
of the blank. If the guide is made of wood a piece of tin or steel 
may be inserted at J to give the marking instrvunent a positive bearing. 
The marking instrument should be thin and sharp. 



12- VI 



SUGGESTIONS AND RIGS 
CHAPTER VI 



SOME HANDY DEVICES 



Box Square 



The accompanying illustration, Fig. 13, shows what is usuall> 
termed a vertical plumb or box square. It is a handy device, which 
will be found very convenient in transferring lines to irregular sur- 
faces which do not lend themselves readily to the use of a square or 




Fig. 1,?. Box Square 



even a flexible rule. The device consists of a box square made of 
wood and shown in Fig. 13. The marker consists of a straight piece 
of hard wood shown in the upper part of Mg. 13,' and in dotted outline 
at the riofht-hand side. 




Fig. 14. Bo.x Square in Use 

This marker has a brad driven into the end and filed to a point, 
as shown at A. Sometimes the point is formed by a metal plate let 
into the face of the marker at the point A. Care should be taken to 
see that the scribing edge is in exact line with the face B. The man- 
ner of using this device for drawing a line across a core box is shown 



A CORE BOX PLANE 



13- vr 



in Fig. 14. This can be used for drawing lines at right angles to a 
center Hne of the box, or at any other angle, as in the case of core 
boxes for pipe angles such as Y's, etc. This form of square is very- 
useful in drawing lines across carved work, as in stove plate patterns. 
Fig. 15 shows the application of a little different form of the box 
square for external work. The square shown in Fig. 13 cannot readily 




Fig-. 15. External Box Square 

be adapted for this class of work on account of the webs C, which are 
used to hold the pieces D and E in place. The form shown in Fig. 15 
receives the necessary stiffening by the pieces A and B which are 
attached to the end of the square proper, which is composed of pieces 
C and D. 

A Core Box Plane 

In the accompanying figures I show a method of making a rabbet 
plane serve as a core box plane. In the lower part of Fig. 16 side and 
end views of the plane are shown, and it will be noticed that a block of 




X^ 



<5 ^-s.^' S 



Fig. 16. Core Box Plane 



hard wood has been screwed to the body of the plane at right angles 
to it, the face of the block being allowed to project slightly beyond the 
sole of the plane, so that it will come opposite the cutting edge of the 
bit. The edge of the block should be gouged out slightly opposite the 
throat of the plane to allow shavings to clear themselves freely. In 
the upper part of the figure the plane is shown in use. 



14-VI 



SUGGESTIONS AND RIGS 



Wooden Calipers 

For calipering large work it is frequently difficult to obtain a pair 
of calipers large enough which will at the same time be delicate enough. 
Large metal calipers are very heavy and hence not as delicate as might 
be desired. Fig. 17 shows a light wooden frame caliper made up of 




Fig. 17. Large Wooden Calipers 



strips of hard wood screwed together and provided with adjustable 
pins made from ordinary dowel pin stock. This device will be found 
very handy indeed for turning large parallel work. 



CROOKED CORE BOXES 
CHAPTER VII 



15 -VI 



SOME HANDY KINKS 

Elbow Core Boxes 

All patternmakers have had to construct core boxes for elbow- 
patterns, and in many cases the pattern is wanted yesterday. This 
means a decidedly hurry-up job. Fig. 18 illustrates one method of 
performing such a hurry-up job. This shows the outline of the elbow 




FIG. 18 



FIG. 19 




FIG. 20 




FIG. 21 



Fig. 18. Elbow Core Box Fig. 19. Wedges Tacked Together 

Fig. 20. Joints Parallel to Parting Fig. 21. Joints Perpendicular to Parting 

core box and also shows the method of construction. The bend, it 
will be noticed, is formed by a series of wedge-shaped pieces — six in 
all — these pieces being fitted in place, laid out, numbered, taken apart 
and then tacked together in pairs, as shown in Fig. 19. They are then 



16- VI 



SUGGESTIOXS AXD RIGS 



band-sawed, taken apart and replaced. The rest — that is, the finishing- 
— is a very easy job. particularly if the ends, A and B, have been band- 
sawed to line. The job can be made still easier by the use of the 
7^ degree wedge, shown at the left of Fig. 2. This can be used 
in each of the separate blocks, in place of tacking them together in 
pairs. 

It will be noticed that the angle of the sides of the wedge block 
is only one-half that of the other wedges. By using this device, the 




Figr. 22, Screws in End Grain 

stock to be trimmed ofif by hand after sawing will be reduced to a 
minimum. 

The old-time way of turning the bend and throwing away one-half 
or three-quarters is much slower than the one here shown. 

Stock for Cylindrical Patterns 

In gluing up stock for cylindrical shaped patterns, it is customary 
to have the joints parallel with the parting, as shown in Fig. 21. 
This is certainly not good practice in many cases, as the parting does 
not remain straight across the grain, while the job is being made. If 
the glued joints are made at right angles to the parting, as shown in 
Fig. 20, there will be very little, if any, trouble from open joints, and 
the pattern will last much longer. 



Screws in End Grain 

When mserting screws into end grain, especially in the case of 
pine, they do not take a very firm hold, especially when the screws 



SCREWS IX EXD GRAIN 17-VI 

h-^vc to be removed frequently as in core boxes where the work re- 
quires the separation of the parts. In such a case the thread formed 
by the screw into the wood will soon become stripped off. A very 
good manner of overcoming this trouble is shown in Fig. 22, in which 
case holes are bored and hardwood plugs inserted, the screws being 
allowed to pass through the plugs at right-angles to the grain. When 
the plugs become badly worn from the repeated removal and reinser- 
tion of the screws, they may be knocked out and new plugs inserted. 



18-VI SUGGESTIONS AXD RIGS 

CHAPTER VIII 
WARPING OF CASTINGS 

The warping of castings, owing to variations in the thickness of 
metal, is an obstacle quite often encountered by the patternmaker, and 
one not always considered by him until his attention is called to a badly 
warped casting and he is asked to explain its cause. The chances are 
that too often he will say "Consult the foundry foreman, for he is to 
blame. They probably lifted the cope off too soon." Or he will make 
some similar statement. 

A good illustration of this kind came under the writer's observa- 
tion not long since, when a casting like that shown in Fig. 23 was to 
be made. In this illustration the casting is shown by the full lines dis- 
torted as it came from the mold, and the dotted lines show the outline of 
the required casting. The distortion has been exaggerated for the sake 
of making it plainer in the illustration. This was one of four sections 
for a floor plate, as used in machine shops doing heavy work, and when 
placed together the four pieces form a surface of 1,024 square feet, 
each section being 32 feet long, 8 feet wide, and 16 inches in depth. 
Each casting weighed 22 tons. In the flanges and lower part of the 
casting the metal was \}i inches thick, while in the upper surface, 
which contained the T slots for the bolt heads, it was about 4^ 
inches thick. 

On inspecting the first casting, it was found to be warped as 
shown in Fig. 23. This warping amounted to F>^ inches in the length 
of the casting. An attempt was made to straighten the casting by 
heating, but it was finally rejected and broken up for scrap. 

The cause of the casting warping to such an extent was then 
discussed and the conclusion reached that, owing to the upper part 
of the casting when molded being of a much lighter section, it cooled 
first. Also the cores for this section tended to counteract shrinkage. 
Later, when the heavy surface containing the slots for the bolts 
cooled it shrunk and sprung the upper surface out of true as shown. 
Of course the piece was molded with the heavy face down in order 
to secure good metal for this finished surface. 

To avoid this warping it was decided to rebuild the pattern which 
was constructed as before, in length about 12 inches longer than 
one-half of the required casting, only that the surface of the pattern 
was made to conform with the warped surface of the first casting, 
except that the pattern was warped in the reverse direction. This 
pattern is shown in Fig. 24, the warp here also being exaggerated 



WARPING OF CASTIXGS 



I9-VI 



for the sake of clearness. When the castings from this pattern were 
taken from the mold they were all that could be desired, as none of 
the four varied more than 54 inch. 

In making the mold a hole was dug for the total length of the 
casting and a half pattern placed in one end of this hole with one end 
blocked up to the required height. It was then rammed and tucked 
up and the two sectional cover flasks A and B, Fig. 25, placed in posi- 
tion and rammed up with the parting between them as shown. Wing 
bars were bolted to the outside of the flasks to support this overhang- 
ing sand. The parting was made at an angle so as to allow the flasks 
to be lifted off and replaced separately. The ramming of this portion 
of the pattern being completed, the flasks were lifted off and marks 




Holt slot core prints— — ==;i^— — - — 



^'iff. 24 




Parting 



rJParting 
B I A 





Fig. 25 

Fig. 23. Warped Casting. Fig. 24. Pattern for Bed Plate 
Fig. 25. Mold for Bed Plate. Fig. 26. T Slot Core Print 



made on the mold opposite the center of the pattern, the pattern 
drawn, turned end for end, and placed in the opposite end of the hole, 
care being taken to see that the center line of the pattern came opposite 
the mark made on the side of the mold. 

As the pattern was constructed 12 inches longer than one-half 
of the casting, this insured a 24-inch bearing upon the portion of the 
mold already completed, and thus assisted in lining up and setting the 
pattern for the second half. After the pattern was in place and tucked 
and rammed up, the flask B was returned to its place, and the flasks 
C and D placed successively in position and rammed up, the partings 
being made as shown. The flasks were then lifted off, the pattern 
drawn, the mold finished, the cores set, gates cut, and all made ready 



20-Vl SUGGESTIONS AND RIGS 

for pouring. In Fig. 25 the pattern is shown in its second position in 
the mold. 

In order to avoid the use of a large number of chaplets on top of 
the cores for the T slots, a very simple device was resorted to. This 
device has been described in the Section on ^Molding in Cores, but is 
also shown in Fig. 26, as applied to this particular case. It will be 
noticed that the core print is wider than the T slot, and hence when 
a core of the cross section of the core print and T slot is placed in 
the opening made by such a core print, and the metal flows into the 
mold, there will be more area exposed in the width A than in the 
width B, and hence the metal which exerts a lifting force under the 
overhanging portions C will be more than balanced by the metal bear- 
ing down on the portions D. When cores are made and carefully set 
according to this system, no chaplets will be needed on top of them, 
and of course after the entire core is submerged it will be held down 
by the metal above it. The cores for forming the interior of the 
casting between the ribs were made separately and set in place before 
the mold was closed. 

The interesting point in this matter is the fact that the pattern 
had to be sprung a certain amoimt to overcome the spring which 
would naturally result in cooling. The exact amount that any pattern 
will have to be distorted to accomplish this result can only be ascer- 
tained by experiment, though experience will enable a patternmaker 
to make a very close approximation at the first trial. The depth of 
cope used may in some cases have an influence on the results. 



DRAWING ARCS OF CIRCLES 21-VI 

CHAPTER IX 

ARCS OF CIRCLES 

In patternmaking it is frequently necessary to draw arcs and 
chords of large circles and in many cases it is not possible to do this 
with trammels from the center. 

An arc of a circle may be defined as any part of its circumference 
and is measured along its circumference. 

A chord is a straight line joining the extremities of an arc. 

A segment of a circle is any part of a circle bounded by an arc 
and its chord. 

These various parts are plainly shown in Fig. 27. It often be- 
comes necessary to lay off angles of a certain number of degrees and, 

.__Are of Circle ___^ 



^ L 



\ ^ 



H Chord ^ -^ a Chord 

Chord of Circle 



\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 



/ 



/ 
/ 

/ 

/ 



/ 

/ 



Figr. 27. .Arc and Chf)rd uf a Circle 

in many cases, especially in large work, the protractor or bevel is not 
accurate enough and in such cases the chord may be calculated for the 
given number of degrees and the largest diameter that the work will 
permit. This insures accuracy and usually saves time over trying to 
do an accurate job with the bevel. To obtain a chord for any given 
number of degrees and a given diameter, refer to any engineer's 
Pocketbook and turn to the table of Natural Sines, take the sine of 
^ of the given number of degrees and multiply this by the diameter 
on which it is to be laid off. 

For example, if it is desired to lay off a chord of 30 degrees for 
a 12-foot circle we would turn to the table and find the natural sine 
of one-half of 30 degrees or 15 degrees. This is .25882, and multiply- 
ing this decimal by 12 feet, the diameter, gives 3.10584 feet. Reducing 
this to inches by multiplying by 12 and reducing to common fractions 
we have Z7 17-64 inches, as the length of the desired chord. 



22- VI 



SUGGESTIONS AND RIGS 



The accompanying table of chords dividing the circle into from 
3 to 100 equal parts will be found very useful and will facilitate the 
laying out of segments, arms of wheels, etc. 



TABLE OF CHORDS 


N 


S 


N 


S 


N 


S 


N 


S 


N 


S 


N 


S 


3 


.86603 


20 


.15643 


37 


.084804 


53 


.059240 


69 


.045515 


85 


.036953 


4 


.70711 


21 


.14904 


38 


.082580 


54 


.058145 


70 


.044865 


86 


.036522 


.S 


.58779 


22 


.14232 


39 


.080466 


55 


.057090 


71 


.044232 


87 


.036103 


6 


.50000 


23 


.13617 


40 


.078460 


56 


.056071 


72 


.043619 


88 


.035692 


7 


.43388 


24 


.13053 


41 


.076549 


57 


.055089 


73 


.043022 


89 


.035291 


8 


.38268 


25 


.12533 


42 


.074731 


58 


.054139 


74 


.042441 


90 


.034899 


9 


.34202 


26 


.12054 


43 


.072995 


59 


.053222 


75 


.041875 


91 


.034516 


10 


.30902 


27 


.11609 


44 


.071339 


60 


.052336 


76 


.041325 


92 


.034141 


11 


.28173 


28 


.11197 


45 


.069756 


61 


.051478 


77 


.040788 


93 


.033774 


12 


.25882 


29 


.10812 


46 


.068243 


62 


.050649 


78 


.040267 


94 


.033415 


13 


.23932 


30 


.10453 


47 


.066793 


63 


.049845 


79 


.039757 


95 


.033064 


14 


.22252 


31 


.10117 


48 


.065401 


64 


.049068 


80 


.039260 


96 


.032719 


15 


.20791 


32 


.098018 


49 


.064073 


65 


.048312 


81 


.038775 


97 


.032381 


16 


.19509 


33 


.095056 


50 


.062791 


66 


.047582 


82 


.038303 


98 


.032051 


17 


.18375 


34 


.092269 


51 


.061560 


67 


.046872 


83 


.037841 


99 


.031728 


18 


.17365 


35 


.089640 


52 


.060379 


68 


.046184 


84 


.037391 


100 


.031411 


19 


.16460 


36 


.087156 



















The quantities in the column headed S are the sines of half the 
angles as already explained. The quantities in the columns headed 
N are the number of equal parts into which it is desired to divide 
a circle. For instance, if it is desired to divide the circumference 
of a gear four feet in diameter for 23 teeth we would look in the 
column N for 23, and opposite this, under S, we would find the decimal 
.13617, multiplying this by 48 inches, or the diameter, will give us 
6.536 inches as the distance to which our dividers should be set. 




Fijj. 28. Graphic Method of Drawing an .^rc 

The radius of a given piece of work is often so great that the 
floor space available is not sufficient to lay out the work, or it would 
be impossible to use a trammel beam of the desired length. In such a 
case as this it becomes necessary to draw the arc of the circle without 
the use of a center. The rise of the arc must first be obtained, and the 
following calculation is one way in which this can be done. Square 



DRAWING ARCS OF CIRCLES 23-VI 

the radius and from this subtract the square of one-half of the chord. 
Extract the square root of the remainder and subtract the result from 
the radius. This will give the rise. 

A graphic method of drawing the arc is shown in Fig. 28. The 
chord is first laid out and from the center the rise is drawn. From 
the center of the chord scribe a quadrant of a circle with the rise as 
a radius as shown. The quadrant should be divided into any conven- 
ient number of equal parts. In the case illustrated, four have been 




Fig. 29. Drawing Large Arcs 

taken. Also the part of the chord A cut by the quadrant should be 
divided into four equal parts and the points connected by the lines 
C, D and E, as shown. Next, each half of the chord should be divided 
into four equal parts, giving the points 1, 2 and 3. Through the 
points 1, 2 and 3 draw lines parallel to C, D and E. From the points 
at which the lines C, D and E intersect the quadrant, draw lines 
parallel to the chord until they intersect the lines from the points 
1, 2 and 3 in the points F, G and H, as shown. These will be points 
on the circumference of the desired circle. Brads can be driven at 
these points and a flexible strip bent along them to be used in drawing 
the arc of the desired circle. 

Another method of describing the arc of a circle without the 
center is shown in Fig. 29. The rise of the arc having been obtained, 
a suitable wooden triangle should be constructed as shown, making 
A-B and C-D each longer than the chord of the arc. Lay off the 
chord and rise on a board and at the extremities of the chord drive 
brads and fasten the tracer point or pencil at the intersection of the 
inner edges of the legs of the triangle and then move the triangle back 
and forth, keeping the legs in contact with the brads. The tracer point 
will then draw the arc required. 



2i-VI SUGGESTIONS AXD RIGS 

CHAPTER X 
CHORDS OF ANGLES 

The accompanying table of chords of angles will be found very 
useful in many operations in both the foundry and patternshop. It will 
also tend to do away with much inaccuracy which is usually the result 
of laying out angles which extend beyond the line of the protractor 
blade. 

To obtain the chord of any angle given in the table scribe an arc of 
a circle with one of the radii given. With the trammel lay off the chord 
of the required angle upon the circumference scribed. Now if lines 
be drawn through the ends of the chord to the center of the circle 
they will represent the angle desired. 

Chords of intermediate angles not given in the table can be obtained 




-3&Rdd * 

Fig. 30. Diagram for Chords of Angles 

by dividing the difference between two given angles, as shown in the 
diagram. Fig. 30. 

Example. — It is required to lay out an angle of 30° 30'. First: 
Draw with a radius of 36 inches an arc BD. The base line AB is 
drawn passing through the center of the circle, and by referring to the 
table the chord of the angle of 30° upon the 31 inch radius is found 
equal to 18 41-64 inches. With this length set off on the trammels 
the chord BC is laid off. The chord of 31° is found to be equal to 19' 
15-64 inches with a trammel set to this distance and B as the center, 
the chord is drawn through D. Next, with the dividers set to any con- 
venient radius the chord CD is bisected and the line drawn through the 
points E and A will give the difference between the two angles, and 
the angle BAE will equal to 30° 30'. 



CHORDS OF ANGLES 



25-VI 



91 
p 

CM 


i, 

o 


rr> Tt u-)vO t-^00 On O w N rO •* 10\0 t-~CO <3\ O m p. r<o ■<* lOvO r~ CO 0^ O O « 
J>. t^ t^ t^ t^ t^ t~»00 OOeOOOOOOOOOOOOOOO 0^a^O^O^O^C^a^O^C^O^O O O 

M W « 


i 


■a 


VO t^ t-CO OOO^a^OO->-lP««r0^o•*■*lO lOvO vO r-- t-.00 00 CT^ <Jn O O O 


00 


-d 


M^o!-*m|t 1— ««- K!-r--»fflM w««-<Ma>[-»i >M|o:M«*«t.Jl" Hk mH-ioH' WJ-»«ltio'?^ ioh*rol-t 
COOOOO ONONJ^OvO O O O '1 'I " ►^ «N M M « rOrOrOrO-n-'^Tj-Tj-loiOU-, 




bb 
5 


M <^ 'O'*- lOvO t^OO On O •- <N '^ -* >Ov£) t^OO CT< O i-i <N f^ tJ- lOvT r^OO Oi O 




-d 


00 0^ O tN fO •* ir>vD 00 CJN O ^ IN ro iOv£) t^OO CT» O M rO -^ "OvO t^OO OO O P< 








00 


-d 




0^0^0 O O w m - M M CS CS rOrOrOrJ-rt'^'^lOlO lO^O vO vO vO t^ t^ r^CO 


be 
a 
< 


Q 


I-" <N f) •* 'OvO t^oO ON O w W rOTt- lOVO t^OO 0^ O i-i M cO Tf iOnO r>.00 On O 


0) 




- M ro lOvO 1^00 O M M rO »OvO t^OO O m P< rO »Ovp t^oO CT\ « « rO '^VO r^ 


CO 

k 


-d 
•a 




03 

3 

00 


-d 


to d^'^^cchoHooH^JH^'^^ FOMpo^i^ r^Nfte**to whoio'w^hHiM' — Hooh«5OT^i&'-d ""r-.^-.ti^ to*"!— 
iO|^iel«,-»H „ M >H « N «S rOfOfO-^'Tf'^iO'O'O 10\0 »^ vO r^ t^ t^OO 00 00 ON O^ 


a 
< 




►H tN| PDTj-iOvO t^OO On O w M tO"<»-ir5VO t^OO 0> O '- C ro ■* »OVO r«.CC ON O 
MMl-lMMMl-lMIHI-lM('fHr«(M(>4C4CN(Mn''. 



2o-VI SUGGESTIONS AND RIGS 

CHAPTER XI 

RIGHT-ANGLED TRIANGLES 

A table of right-angled triangles, which will be found convenient 
in laying out large pattern and plate work, is given below. 

In erecting a perpendicular at a given point upon the base line 
A B, Fig. 31, select from the table the triangle of the most suitable 
proportions to suit the work. Say for illustration we select the fifth 
from the top of the table. This is a right-angled triangle, the propor- 
tions of which are 8, 15 and 17. 

From the desired intersection C with the base line A B lay off 




Fig. 31. Right-angled Triangle 

the point D which would be equal to 15 feet. Now with the trammels 
set to an 8-foot radius, and C as the center, scribe the arc of circle E. 
With D as the center and the trammels set to a 17-foot radius scribe 
the arc of a circle F giving the point of intersection G and we have the 
perpendicular line C G accordingly. 



■5 

c ^ 

Pi 


1) 

a 

m 


11- 

X 


-5 




X 


3 


4 


5 


15 


20 


25 


5 


12 


13 


15 


36 


39 


6 


8 


10 


15 


112 


113 


7 


24 


25 


16 


30 


34 


8 


15 


17 


16 


63 


65 


9 


12 


15 


17 


144 


145 


9 


40 


41 


18 


24 


30 


10 


24 


26 


18 


80 


82 


11 


60 


61 


19 


180 


181 


12 


16 


20 


20 


21 


29 


12 


35 


37 


20 


48 


52 


13 


84 


85 


20 


99 


10] 


14 


48 


50 









POLYGONS 27-VI 

CHAPTER XII 

A TABLE OF POLYGONS 

This table of polygons will be found very useful in shop practice. 
It has been arranged in this handy form so as to save as much calcula- 
tion as possible. 

The diagram, Fig. 2)2, shows quite clearly what is meant by the 
words "diameter" and "sides." The formulas may be explained — if 
additional explanation is found necessary — by the following : 



A TABLE OF POLYGONS 


No. of 
Sides 


Coef. 


No. of 
Sides 


Coef. 


No. of 
Sides 


Coef. 


No. of 
Sides 


Coef. 


No. of 
Sides 


Coef. 


No. of 
Sides 

128 


Coef. 


3 


1.16 


28 


8.93 


53 


16.88 


78 


24.83 


103 


32.79 


40.75 


4 


1.41 


29 


9.25 


54 


17.20 


79 


25.15 


104 


33.11 


129 


41.07 


5 


1.70 


30 


9.57 


55 


17.52 


80 


25.47 


105 


33.43 


130 


41 38 


6 


2. 


31 


9.88 


56 


17.83 


81 


25. 79 


106 


33.74 


131 


41.70 


7 


2.31 


32 


10.20 


57 


18.15 


82 


26.11 


107 


34.06 


132 


42.02 


8 


2.61 


33 


10.52 


58 


18.47 


83 


26.43 


108 


34.38 


133 


42.34 


9 


2.93 


34 


10.84 


59 


18.79 


84 


26.74 


109 


34.70 


134 


42.66 


10 


3.24 


35 


11.16 


60 


19.11 


85 


27.06 


110 


35.02 


135 


42.98 


11 


3.55 


36 


11.47 


61 


19.42 


86 


27.38 


111 


35.34 


136 


43 29 


12 


3.86 


37 


11.79 


62 


19.74 


87 


27.70 


112 


35.65 


137 


43.61 


13 


4.18 


38 


12.11 


63 


20 06 


88 


28 02 


113 


35.97 


138 


43.93 


14 


4.49 


39 


12.43 


64 


20.38 


89 


28.33 


114 


36.29 


139 


44.25 


15 


4.81 


40 


12.74 


65 


20.70 


90 


28.65 


115 


36.61 


140 


44.57 


16 


5.12 


41 


13.06 


66 


21.02 


91 


28 97 


116 


36.93 


141 


44.88 


17 


5.44 


42 


13.38 


67 


21.33 


92 


29.29 


117 


37.25 


142 


45.20 


18 


5 76 


43 


13.70 


68 


21.65 


93 


29.61 


118 


37.56 


143 


45 52 


19 


6.07 


44 


14.02 


69 


21.97 


94 


29.93 


119 


37.88 


144 


45.84 


20 


6.39 


45 


14.33 


70 


22.29 


95 


30 24 


120 


38 20 


145 


46.16 


21 


6.71 


46 


14.65 


71 


22.61 


96 


30.56 


121 


38.52 


146 


46.48 


22 


7.03 


47 


14.97 


72 


22.92 


97 


30.88 


122 


38.84 


147 


46.79 


23 


7.34 


48 


15.29 


73 


23.24 


98 


31.20 


123 


39.16 


148 


47.11 


24 


7.66 


49 


15.61 


74 


23.56 


99 


31.52 


124 


39.47 


149 


47.43 


25 


7.98 


50 


15.93 


75 


23.88 


100 


31.84 


125 


39.79 


150 


47.75 


26 


8.30 


51 


16.24 


76 


24.20 


101 


32.15 


126 


40.11 


151 


48.07 


27 


8.61 


52 


16.56 


77 


24.52 


102 


32.47 


127 


40.43 


152 


48.39 



To obtain the length of a side : Divide the diameter of the circle 
by the coefficient. 

To obtain the diameter : The length of the side is multiplied by 
the coefficient. 

To obtain the coefficient : The diameter of the circle is divided by 
the length of the side. 

This table will be found convenient in obtaining the chords of 
segments and similar work. 



28-VI 



SUGGESTIOXS AND RIGS 




Coefficient = 



Dia m. 
Coef. 



Dlam. = Coef. x Side 



Fig. 32. Polygon Diagram 



BEGINNING A PATTERN 29- VI 

CHAPTER XIII 

GENERAL SUGGESTIONS 

Under the above heading the writer has arranged a number of 
remarks and suggestions pertaining to patternmaking, which, if given 
careful consideration and combined with a fairly good streak of self- 
confidence, will go a long way toward the make-up of a thorough and 
proficient workman. To become a good patternmaker one must become 
to some extent an engineer. He must be somewhat informed upon the 
principles of machine design and the construction of various kinds of 
machinery, and he must have a thorough knowledge of molding and 
also a knowledge of drawing. By the latter I do not mean merely the 
making of drawings or layouts which are copies of the drawings fur- 
nished by the designer or draftsman, but an understanding of the prin- 
ciples of projection as applied to geometrical figures. 

He must be able to read any mechanical drawing readily and form 
a clear idea of what the draftsman intended to convey by the drawing 
and he must also comprehend all of the details to the minutest degree. 

To become an expert in the handling of tools, which is one of the 
necessary requirements of the trade, it is only acquired by constant 
practice for a long time, and this practice is usually accompanied by 
scarred fingers. 

What to Observe When Beginning Work Upon a Pattern 

Upon receiving a drawing for a pattern to be made, note the 
metal to be used for the casting and the number of castings to be made. 
The number of castings to be made will determine whether a tempor- 
ary, medium or standard pattern is required and will also determine 
the method of construction. The construction of the pattern should be 
governed in such a way as to produce a casting with the smallest 
expenditure of time, labor and material, in both the pattern shop and 
the foundry. In many cases extra time spent in the pattern shop in 
making a better pattern will be more than saved in the foundry, or vice 
versa. Next, check all of the intermediate or minor dimensions to see 
whether they agree with the over-all dimensions. This will often save 
trouble later on as an error is corrected more easily on paper than in 
v.'ood or metal. 

If detailed drawings of a machine or other device to be constructed 
are received they should be accompanied by a general drawing and this 
should be looked over and the general arrangements and dimensions 
checked. 



30-VI SUGGESTIOXS AXD RIGS 

Temporary patterns are those not likely to be used more than 
once. They should be made with as little expenditure of labor and ma- 
terial as possible to produce the required casting. Unless there is 
plenty of space in the pattern loft this grade of patterns should not 
be preserved, but taken apart and the material used up, if possible. 

Medium patterns are that class of patterns likely to be used 
occasionally and hence more care should be taken in their construction 
than in the case of the class already mentioned, as they are required 
to withstand more hard usage in the foundry, as well as the distortion 
likely to occur during the storage in the pattern loft. 

Standard patterns are those which are frequently used or in con- 
stant use and no pains should be spared in their construction, as they 
cannot be made too substantial. 

Economical Use of Lumber and Supplies 

If dififerent grades of material are provided they should be used 
with discretion. Knots and shaky material will not affect the inside 
of a box or framed up pattern. When the pattern to be made is of 
large size, special provision should be made for rapping and drawing 
it. If the pattern is too large to handle and store conveniently, it 
should be made in sections which are pinned and bolted together during 
the construction of the pattern. 

The Layout Board 

This should only be used for such work or such sections of work 
as absolutely require it. For instance, in the making of web patterns 
or when there is a surface which can be laid out and the material then 
gotten out and laid down to this outline and worked to it. In such a 
case one layout answers both for the determination of the dimensions 
and for the fitting of the stock. 

Center Lines 

I wish to place proper stress upon this point in patternmaking, 
as it is one that is often overlooked. Prominent center lines should 
be scribed on all sides of the pattern and across the joint. If this is 
carefully observed the chances of error will be greatly reduced and the 
checking of the pattern facilitated. It will also improve the disposition 
of the pattern checker. 

Contraction 

The contraction or shrinkage should be carefully considered. The 
shrinkage of castings is to a large extent governed by their form and 
the met^l distribution. The presence of dry sand cores in the mold has 



SHRINKAGE 31-VI 

a tendency to retard or resist the shrinkage. Hard iron or steel will 
shrink more than soft iron. Yellow brass will shrink more than bronze, 
etc. Castings of a cylindrical or box section will shrink more in length 
than in diameter, that is, more along the core than across it, the 
shrinkage in the diametrical direction or at right angles to the core 
being retarded or resisted by the dry sand core. It is good practice 
in cases of this kind to allow one-half of the standard shrinkage for 
the diameter of the cylinder or across the box section. 

Shrinkage for Cast Iron 

The conventional allowance for the shrinkage of cast iron is 
3-32 of an inch per foot for ordinary work. When castings assume 
large proportions, such as heavy engines or generator frames and 
large cylinders, the shrinkage is reduced, owing to the swelling of 
the mold, on account of the great pressure of the iron. Patterns for 
large cylinders are usually made with a 1-12-inch allowance per foot 
for shrinkage, while heavy engines or generator frames receive but 
1-16 of an inch per foot. Heavy hammer blocks and counter weights 
are usually made with a standard rule, in other words, with no allow- 
ance for shrinkage. 

Shrinkage of Steel Castings 

The shrinkage of steel castings is not to be relied upon as a con- 
stant. The usual allowance is 3-16 of an inch per foot, but it is subject 
to frightful variations. Plain straight castings will often shrink from 
54 to 5-16 of an inch per foot, while in dry sand cored molds they 
will not shrink more than ^ of an inch per foot. When, however, 
a contraction of only ^ inch is allowed, a liberal allowance should be 
made for finish upon all surfaces to be machined to insure the proper 
dimensions should the shrinkage of the castings exceed the contraction 
allowed. In many cases the shrinkage appears to be an ungovernable 
element and is apt to vary either way. As a consequence, what is 
usually termed "playing safe" is generally resorted to, that is, the back 
of the outer flange is thickened up to counteract or overcome the bad 
results which would result if the shrinkage should exceed that allowed, 
for in the latter case the flanges would finish up too thin. It is 
better in most cases to have the flanges a trifle over thickness than 
below thickness. It will also be found well to make the outlaying 
pads a little wider than the drawing calls for. 

Tie pieces or tie bars are placed upon the castings to prevent 
the spreading of certain parts in cooling, or to assist the shrinkage 
when such parts are separated by dry sand cores. These tie bars are 



32-VI SUGGESTIONS AND RIGS 

more applicable to and, in fact, are an essential feature in the production 
of good steel castings, as in the latter class of castings shrinkage 
plays such an important part. 

The introduction of these bars is really a point in molding that 
should be taken care of by the foundryman who is supposed to make 
such provisions as are necessary to produce a casting true to pattern, 
but provision for these pieces should be made in the core box or upon 
the pattern. If these precautions are not taken and the casting is 
delivered to the machine shop badly out of shape, the pattern shop 
will no doubt hear about the amount of finish it allowed. 

Amount of Finish 

The finish to allow is oftentimes a troublesome problem for the 
patternmaker. The amount that will satisfy one machinist will not 
satisfy another. The proper amount of finish depends to a great extent 
upon the size of the piece to be machined, the method of casting, and 
whether or not it is turned out like the pattern. It is advisable to 
make this allowance as small as possible, but at the same time to 
leave sufficient material for the proper finishing of the casting. As 
a rule, iron castings which are produced in loam molds and castings 
made from steel are apt to vary from the proper dimensions more than 
those molded by other methods. 

Steel castings or loam molded iron castings should receive an 
allowance of from }i to y^ inch for finish and this should be sufficient 
for ordinary sized work. F"or the general run of green sand cast- 
ings from 3^ to 34 inch should be an ample allowance. For small brass 
and machine molded iron castings which are of sound metal 1-16 of 
an inch should answer. 

Tool Clearance 

The patternmaker should consider the method in which the casting 
is to be finished or machined and then see that the proper tool clear- 
ance is allowed wherever it is required, as for instance, at the ends of 
all surfaces to be planed or milled. A little thought expended on this 
point will save many hours of chipping in the machine shop. Some 
unscrupulous fellow will say, "Oh, that's none of my business. They 
should look after the machining of the castings." This is not the 
proper spirit for the patternmaker to exhibit, as he should have an 
interest in the casting clear through to the final erection of the machine. 

Construction of Patterns and Core Boxes 

Having discussed some of the allowance and provisions for the 
molding and machining of castings, let us proceed with the pattern 



CORE PRINTS 33-VI 

and core box work, taking up a number of points which will facilitate 
this work and economize material. These points will also serve to 
save time in the foundry. 

Machines are placed in the pattern shop to do the work and hence 
the patternmaker should see that the machines do the work and thus 
save his own strength and labor. 

Glue is an indispensable material in pattern construction, but it 
should be applied with judgment, as there is a time to use glue and a 
time to let it alone. Many a badly warped pattern can be traced to 
the manner of gluing up the stock. Cross gluing should be avoided 
wherever possible, for if any shrinkage or swelling takes place in such 
a case a distorted or twisted pattern will surely result. Unnecessary 
gluing often causes no end of trouble and expense when an alteration 
or change is to be made upon a pattern. Screws may appear more 
expensive than a few nails or a few spots of glue, but it is not always 
so, and their use should be encouraged. 

Core Prints 

This is one of the knotty problems for the patternmaker to solve, 
but we will not attempt to settle it this time. The length or width of 
a core print that will answer one molder to a nicety will not suit another 
at all. The writer, however, believes in a good liberal allowance for 
all core prints, despite the fact that patterns often come back from the 
foundry with a portion of the core print missing, it having been sawed 
off by the foundry carpenter so that the pattern could be used in a 
certain flask. Of course the length of any core print should be gov- 
erned by the size or the diameter of the core to be set. When con- 
structing core prints of irregular form, care should be taken and 
provision made so that their outline can be readily transferred to a 
core box, that is, such core prints should be built upon certain properly 
determined lines and these lines noted on the layout. This method 
of working will avoid the use of templets and other troublesome devices 
which are often employed when such precautions are not taken. A 
core print and core should be so marked and so constructed that there 
is no chance of placing it in the mold in any position except that in 
which it is intended to go. This point is often overlooked by the 
patternmaker and rarely detected by the molder unless the difference 
is quite noticeable. 

Loose Pieces 

Loose pieces on patterns, although objectionable, cannot always 
be avoided and in many cases would be found more economical and 



3i-VI SUGGESTIONS AND RIGS 

less objectionable than a core. When it becomes necessary to choose 
between the two methods of using a loose piece or a core it will gen- 
erally be found better to use the former, because it will insure a truer 
casting and avoid the scare caused by the introduction of a dry 
sand core. 

If loose pieces or core prints are attached by two dowel pins of 
different diameters, the error, often caused by the molders or core- 
makers attaching pieces in the wrong position, will be avoided. All 
loose pieces or core prints should be marked or numbered plainly so 
that their respective positions can be determined at a glance. It is 
also good practice to scribe a good, heavy line around them. This only 
takes a moment, but it will often save the molder or co remake r many 
a minute's search for the location of a detached loose piece. 

The length and diameter of the core should also be marked upon 
the core print when standard sizes are used, as the molder rarely has 
a pair of calipers always at hand, as is the case with the patternmaker. 

In the case of circular work when cores are used around the 
interior or outer diameter of a large pattern the patternmaker should 
mark the number of cores required to complete the circle upon the 
pattern and upon the core box. This will show the coremaker instantly 
the required number of cores to be made and save him the time and 
trouble of stepping the distance off around the pattern. When a special 
core is to be used and the core print does not distinguish it from the 
regular standard foundry core the core print should be marked "special 
core." This will often save the necessity of replacing the casting. 

When making gear patterns it is well to get out several extra 
teeth, bore a small hole through them and attach them to the pattern. 
This will often save the pattern from mutilation by having several 
teeth ripped off by the molder should the pattern fail to draw properly. 

Another method of saving the pattern from abuse is to get out 
a block five by three inches by two inches thick, with one side cut to 
conform to the inner diameter of the rim of a gear pattern. The 
molder is supposed to place this block against the inside of the rim 
and then rap upon it with a hammer. Of course this rapping is done 
after the cope has been lifted off. By this device the pattern can be 
well rapped without injuring it. 

In looking up gears in the pattern loft it will often be found con- 
venient to have the patterns marked on each side of the rim with the 
pitch diameter, circular pitch, width of face and number of teeth. 

Old Patterns 
These should always be treated with suspicion, as they are not to 



CORE BOXES 35-VI 

be trusted, and have proven the pitfall of many a good workman. 
Previous alterations are not always noted on the drawing and distor- 
tions are very apt to occur during storage. For these reasns an old 
pattern should be checked over thoroughly when making new additions. 
Alter old patterns cheerfully, for though it is not a clean and agreeable 
job. some of us must do it. so do it graciously, but we will not blame 
you for kicking if you get more than your share. 

Core Boxes 

Whenever the circumstances permit core boxes should be con- 
structed of rectangular form and filled in with the necessary material 
to produce the required form of core. This manner of construction 
of core boxes will be found advantageous and convenient in many 
respects, and it will also save material, for when a good rigid frame 
is constructed to begin with it can be filled in with material almost of 
a temporary character, for such material cannot get out of place when 
supported by the frame. This construction also saves the box from the 
punishment it receives by rapping, for all that is required when the box 
has been rammed up is to remove the screws from the opposite corners 
of the frame and draw the frame away. The handling and the clamp- 
ing of the box to the core plate is also facilitated by its rectangular 
form. The material which forms the core box proper should be fitted 
loosely in the frame, as it will have a tendency to swell and tighten 
itself up. 

Keep the length and width of your core box scant, as the core 
would be liable to swell. 

Bottom boards for core boxes should be made only when the form 
of the core requires it. The construction of bottom boards is usually 
only a waste of time and material and they are often thrown aside by 
the coremaker, for they cause b.im an unnecessary roll over if used, 
where by the use of the core plate the core is rammed up on the plate, 
plate, the box removed and the cores sent direct to the oven. 

• These suggestions are only a drop in the bucket in comparison 
to the number of little big things that serve to make up successful 
patternmaking and that present themselves day after day to every 
workman. 

By all means think for yourselves, think twice before you do it. 
and then do not do it until you know why you are doing it. 

Don'ts 

Don't start your job until you have it well in mind, or you may 
strike a snag later on. 



36-VI SUGGESTIONS ASD RIGS 

Don't proceed with the pattern without noting the metal of which 
it is to be cast. 

Don't fail to inquire whether the grade of pattern is temporary, 
medium or standard. 

Don't forget that the art of quick patternmaking lies in knowing 
where to slight it — but 

Don't form the habit of slighting everything. The man that can 
work according to his job is a valuable man. 

Don't trouble the "Boss" with fool questions. He has troubles 
of his own, besides you may expose your ignorance — at the same time 

Don't try to get along without really necessary information on 
the job at hand, which the Boss may have neglected to give you. 

Don't make unnecessary layouts of work above all. 

Don't take time to lay out a job, then not use the layout ; ]:)roperly 
used, it will save time on the job. 

Don't fail to study economy both of material and time ; both cost 
your employer money. 

Don't miss checking up all dimensions on the drawing before pro- 
ceeding with pattern. 

Don't make a pattern without knowing how it is to be molded, 
simply because the old man told you to. 

Don't accept your first inspiration as to the molding and construc- 
tion of a pattern ; try and think out another way. 

Don't start a job you don't see through, expecting to get an 
inspiration as you go along. This idea wears out the floor between 
your bench and the old man's desk. 

Don't construct large patterns without provision being made for 
handling, shipping or storing. 

Don't be stingy with your core prints. 

Don't be afraid that well defined center lines will spoil the looks 
of your job. They will look good to the checker, and to the lad who 
may have to change the job later. 

Don't fail to put center lines on your core boxes, as well as your 
patterns. A pattern like "Bread that is cast on the waters is seen 
again after many days," and it may be up to you to change it. 

Don't pick out all the snaps for yourself, when you have help on 
a job. However good you may be — 

Don't forget there are others. 

Don't despise the help of the apprentice on the job. He did not 
come in simply to learn to varnish, so let him do things. If he falls 
down, pick him up, and — 



THINGS TO REMEMBER 37-Vl 

Don't forget you had troubles, and when you are a has been, he 
may help you. 

Don't think that you know it all ; there are other men that know 
a little. 

Don't do by hand that which the machine should do, but you 

Don't have to wait your turn at the band-saw to cut off a tooth- 
pick. 

Don't fail to study your machines and how to gjt the most out 
of them, but 

Don't take liberties or long chances with the jointer, especially 
when the knives are dull. 

Don't take long chances on the lathe, remember the adage, "An 
ounce of prevention is worth a pound of cure." 

Don't waste time setting bevels for standard cuts that are arranged 
for on the saw table or trimmer. A little mental calculation and the 
indicator is better. 

Don't think because you see a circle on the drawing that the work 
fnust be done in the lathe ; other pieces fit on sometimes, and 

Don't forget that a sharp band-saw is a good tool and sawing to 
the line, not quite a lost art. 

Don't use your material for a footstool before working it up. It's 
hard on the machines. 

Don't wait until the rip or band-saw is just sharpened, then saw 
nails ; if it must be done, do it before. 

Don't swear when your plane hits a nail. The chances are you 
put it there yourself. 

Don't sandpaper each piece as you put it on the pattern, then 
plane it afterwards. It takes time to sharpen tools, and — 

Don't forget you buy your own. 

Don't round up the ribs and corners of a pattern until all pieces 
have been assembled. 

Don't throw too much work on the foundry, but occasionally a 
little stopping off saves time, and — 

Don't leave the making of the stop-off piece to the foundry car- 
penter ; he may not see things as you do. 

Don't glue two pieces of wood together that have just come out 
of the ice box. It's too chilly on the glue. 

Don't carry your tools in a collar-box and expect the steady pins 
to furnish the ones you haven't got. 

Don't borrow tools and forget to return them, and especially — 

Don't borrow when the other man is not looking. 



38-VI SUGGESTIOXS AXD RIGS 

Don't assume any pattern is correct ; treat them all with suspicion 
until proven. 

Don't proceed with the alteration of an old pattern, without first 
carefully checking it up. 

Don't proceed with another workman's job without checking his 
measurements. 

Don't use screws when nails will do the work as well ; nails go 
quicker and are cheaper. 

Don't forget that supplies and lumber cost money ; if the other 
fellow is paying for it — so 

Don't fail to practise economy, and 

Don't lug in a 16-foot plank and cut 4 or 5 inch print out of 
the middle ; it's easier to turn over the scrap pile. 

Don't keep your bench so littered up that it takes 5 or 10 minutes 
to find some small tool you just laid down. 

Don't think (if you happen to be a relative of one or more of the 
firm) that you are entitled to more privileges than any other man. 

Don't try to do as little as you can for the most you can get, and — 

Don't do any fooling during working hours ; you are paid for 
working — not playing. 

Don't fail to report promptly when your job is completed. 

Don't stand around and look wise when waiting for a job. Get 
busy with your oil-stone. There are always tools to be sharpened. 

Don't fail to check up your pattern when complete. 

Don't leave your mistakes for others to find ; find them yourself, 
and if you do — 

Don't let them go on a chance of its getting past the checker. 
Be sure your sins will find you out, even if it does rope in the other lad. 

Don't say "that is near enough." 

Don't fail to number and place location marks on all loose pieces 
of pattern and core boxes. 

Don't forget to place a marker upon the core print, if the core can 
be reversed. 

Don't fail to nail the lead letters and numbers on the pattern ; 
one nail in each letter is not enough to ensure their staying right 
side up. 

Don't number the core boxes upon the face of box ; sand in time 
will wear it off. 

Don't size up your job and guess at the amount of lumber ; keep 
account of the boards as you cut them up. 

Don't forget an easy way to figure lumber is multiply the length 



THINGS TO REMEMBER 39-VI 

in feet by the width in inches, by the thickness in inches, and divide 
by twelve— example : 9 ft. X 8 in. X 1>4 in. ^ 12 = 9 ft. 

Don't forget to mark upon the side of core boxes which way lift- 
ing hooks for the core are to be placed. 

Don't forget to mark the length of standard cores upon pattern 
when used. This saves the molder's time, as well as the coremaker's. 

Don't waste time doing unnecessary work. 

Don't spend time and money giving patterns a piano finish — they 
are not used for ornaments. 

Don't get into a rut of doing any certain work ; try and improve 
upon your method, as well as lessen the time. 

Don't think you know more than the boss, even if you do. 

Don't expect the highest wages, unless you can produce the goods. 

Don't make a practice of being late to work. 

Don't do government work in the Company's time. 

Don't keep one eye on the boss and another on your job ; it's 
difficult to watch them both. 

Don't take off your apron and look for a chance to wash ud before 
quitting time. 

Don't dig ditches in the grindstone. 

Don't touch a broken band-saw until the machine has stopped 
running. 

Don't leave the jointer with a heavy cut on ; run the table up. 

Don't make the final calipering of your work while the lathe is 
running. 

Don't use double-ended turning tools, they are dangerous. 

Don't forget that a tooth plane bit makes an excellent turning 
chisel for straight work. 

Don't forget that dowel pins belong in the cope half of pattern. 

Don't fail to secure your work well in the lathe either between 
centers or on the face plate. 

Don't stand directly in front of the rip-saw, when sawing; they 
sometimes kick. 

Don't provide bottom boards for core boxes unless necessary ; they 
are often a waste of time and material. 

Don't forget to make your core boxes scant in length and width, 
as cores, when drying, usually sag and swell. 

Don't fail to make the necessary provisions for rapping and draw- 
ing the pattern. 

Don't forget to allow ample material for finishing the casting. 

Don't forget to consider how the casting is to be machined, and 
provide necessary tool clearance. 



40-VI SUGGESTIONS AND RIGS 

Don't forget to put in tie pieces when required, to keep castings 
from spreading or cracking. 

Don't fail to consult the molder; his suggestions may be helpful, 
and we cannot do without him. 

Don't forget that the molder will always try to blame the pattern- 
maker for his own mistakes, if he possibly can, and — 

Don't forget that the molder is in a position to show you your 
shortsightedness, so 

Don't fail to consider the convenience of the molder and coremaker 
at all times. 

Don't think that your own time spent in the foundry is wasted; 
it may or may not be, it lies with yourself. 

Don't be too important to do insignificant work. 

Don't fail to have confidence in yourself, but 

Don't think you are a patternmaker because you have been inside 
a pattern shop. 

Don't lose your head when anything goes wrong; other people 
have made mistakes. 



THE ELLIPSE 

CHAPTER XIV 

STRIKING AN ELLIPSE 



41-VI 



Various and curious have been the devices contrived for striking 
an ellipse, and the fact does not seem to be universally known that the 
.true way is the simplest. Fig. ZZ shows how it can be done with the 
ordinary steel square, or in fact most anything that is handy, having 
two of its edges at right angles, and a thin stick, say about yi x yz inch, 
a little longer than one-half the major diameter of the ellipse. 

Take the pieces you wish to lay out the ellipse on, mark off the 
center lines, also the major and minor diameters, transfer the lengths 
of the semi-major and semi-minor diameters to the stick, driving in 




Fig. 33. Striking an Ellipse with a Square 

two fine brads at these points. Next, place the square on the center 
lines, the intersecting outer edges at the center of the ellipse, drive in 
three small brads as shown in b\, hi and bZ; which will secure the 
square in position. Then placing the stick in position the two brads, 
which project through the under side slightly less than the thickness 
of the square bearing against the two outer edges, move carefully to 
the right and the tracer will mark out one-quarter of an accurate 
ellipse. The draughtsman can do the same thing on his drawing by 
utilizing his set square or triangle and thumb tacks, two pins and a 
sliver. 

Fig. 34 illustrates the same principle, the application being slightly 
different. Take a piece of wood, large enough to make one-quarter 



42-VI 



SUGGESTIONS AND RIGS 



of the ellipse, trim off one end square with one edge, placing the end 
against the edge of another piece of the same thickness, that is straight 
on one edge, brad them lightly to the table, taking a narrow strip and 
driving through it two brads, as stated in Fig. 33, placing the tracer 
at the end of the stick, draw to the right, allowing the brads to slide 




Fig. 34. Device for Striking an Ellipse 

closely on the inside edges of the two pieces of stick, and the result 
is the same as Fig. 33, by simply reversing the pieces you can get the 
other parts, or you can cut out the quarter and use it as a templet. It 
is exactly the same as an ellipsograph and just as accurate; but how 
often do you rub against a patternmaker with one in his kit? Some 
are minus other things more essential than ellipsograph; but a few 
brads and a stick are always at hand. 



o4l 




Fig. .i5. Turning an Elliptical Valve 



Fig. 35 is an illustration of turning up in the lathe an elliptical 
valve which will fit accurately in a circular pipe at an angle of say 45 
degrees. Having the diameter of the pipe which is the minor diameter 
of the ellipse, ascertain the major or long diameter by laying out the 



THE ELLIPSE 



43-VI 



angle ; cut out of a piece of stock the required thickness of the valve, 
an approximate ellipse, leaving sufficient stock on the edges for turning 
off ; then take two pieces large enough to take in the butterfly and tail 
stock centers and of sufficient length and rigidity, fasten them securely 
in the center of the piece for the pattern, at an angle of 45 degrees, cen- 
ter the ends and proceed to turn. It is not as difficult as it looks (the 
dotted lines in sketch showing the exact contour of the edge as the 
piece revolves), and with a modern screw feed lathe, would be a cinch. 
This is a very quick way and will insure a perfect fit in the pipe. 

Fig. 36 is a fairly good approximate layout of an ellipse by the 




Fig. 36. Approximate Ellipse 



divider route, A B is the major and C D the minor axis of an ellipse. 
Space off B E equal to the semi-minor axis CO, using AE as radius for 
the arc at each end of the minor axis. Bisect EO at F and space off 
EG equal to EF and use GB as radius for the arc at each end of the 
major axis. This is a very good approximate method, very nearly ap- 
proaching perfection when the dift'erence in length of each axis is not 
great. 



44-VI SUGGESTIONS AND RIGS 

CHAPTER XV 

SAWING LAGS 

Most patternmakers determine the angle at which to set the fence 
on the circular saw when sawing lags by trial or by guess. This method 
is certainly not satisfactory, especially when there is such a simple 
solution available. In the first place, to get the best results the lags 
should be made as narrow as is consistent with good work. After the 
lags have been cut to width and the sides to the proper angle, it is 
necessary to concave the inner surface. This is usually done by 
passing the lag diagonally across the circular saw. It must be borne in 
mind, however, that when cylinders are cut at angles other than 90 
degrees the result is the outline of a true ellipse, and hence it is evident 
that this method would only give an approximately true circle. 

To determine the proper angle at which to set the fence on the 
saw table, a circle representing the saw should be laid off as shown at 
"A" Fig. 37. The depth of the cut should be laid off as shown at "B" 




t-iO.37 



and the chord "C C" drawn. With one end of the chord "E" as a 
center and with a radius equal to the inside width of the lag an arc 
of a circle should be drawn. A tangent as shown at "D D" should 
then be drawn touching this arc and passing through the other end 
of the chord "C C." The bevel should then be set at the angfle 
"D D C C," which will be the proper angle to use in setting the fence 
on the saw table. 

If the depth "B" is yi of an inch or less, as at "F," Fig. 38, the 
surplus stock can be removed by a series of cuts over the saw ; but if 
■"B" is more than j4 of ^^ inch, most of the stock should be removed 



SAWING LAGS 



45-VI 



by making the two cuts through the center from the right and left, as 
shown at "G," Fig. 38, thus cutting out a triangular-shaped piece and 
preparing the work for finishing in the usual manner. 

The best results are obtained by using a sharp saw with a good 
spring set, and there is nothing to be gained by taking cuts so deep 
that the stock is partially burned and torn out. It would be best if the 
last cut does not exceed 1-64 of an inch in depth, providing the cut is 




Fig. 38 



narrower than the inside face of the lag ; for if it is attempted to cut 
the entire face of the lag, the stock will shift as it is being passed over 
the saw, settling down after the bearing of the rear portion has been 
reduced and the front end of the sawed surface comes to a bearing 
upon the table. 

By carefully observing the rules given work can be finished in a 
superior manner, and there is no better or quicker method of making 
core boxes of large diameter and considerable length than by building 
them up of lags upon half heads. 



INDEX 



A 

SEC. PACK 

Arcs of circles \"I 21 

B 

Bearing, Core box for heavy engine 

bed I 56 

Ued plate, Casting of large \'I 19 

Bevel gear patterns. Construction of.IX' 32 

Bevel gears I\ 18 

Bevel gears, Laying out teeth of...I\' 20 

Box square, A \'I 12 

c 

Caliper, Large wooden \'I 14 

Castings, Rig for producing cylin- 
drical V 31 

Castings, Warping of \'I 18 

Cheeking off end of engine bed 

pattern I 59 

Cheeking off mold for havi'ser pipe. V 18 

Chilian mill mortar pattern V 47 

Chords of angles. Table of XI 25 

Chords, Table of VI 22 

Circles, Arcs of \'I 21 

Cock, Molding a tliree-way II 14 

Core bo.x and clamp combined \'I 6 

Core box plane VI 13 

Core boxes, Construction of VI 35 

Core bo.xes for a double piston valve 

cylinder I 35 

Core boxes for a heavy engine bed. I 44 
Core boxes for a low pressure 

cylinder I 9 

Core boxes for a jiiston valve 

cylinder I 24 

Core boxes for elbows VI 15 

Core boxes for round flasks II 12 

Core boxes for throttle valve V 5 

Core boxes from pattern with plas- 
ter paris, Making of II 3 

Core for suction chamber, IMaking 

of a Ill 9 

Core prints VI 33 

Core prints In sweep work. Use of. Ill 4 
Cores for a slide valve cylinder. 

Arrangement of I 4 

Cores, Casting round flasks in II 11 

Cores, Molding a three- way cock in. II 14 

Cores, Molding in II 1 

Cores, Molding in II 23 

Cores, Molding large gear wheels in II 30 



SEC. PAGE 

Cores, Molding of a large steel 

cutter head in II 26 

Cores, Molding propeller wheel in. II 25 

Cores, Molding of rope sheaves in. II 28 

Cores T slot and name plate II 20 

Cores for large work, Stacking of . . II 7 

Cores, Use of covering II 17 

Cores, Use of nail II 34 

Coupling pins in cores, Molding of a 11 1 

Cross templet work ^' 14 

Cylinder pattern, A piston valve... I 16 
Cylinder, I'attern for a double pis- 
ton valve I 30 

Cylinder, Pattern for low pressure.. I 7 

Cylinder, Pattern for slide valve... I 1 

Cylinder, Sweeping a plain Ill 1 

Cylindrical castings, Rig for pro- 
ducing ^' 31 

D 

Uelinitions relating to gearing IV 1 

Don'ts yi 35 

Drum mold. Sweeping a cylindrical 

and conical Ill 24 

Drum pattern. Cutting the score 

in a VI 1 

E 

Elbow core box ^'I 15 

Elbow, Making a crooked V 56 

Ellipse, Striking an \'l 41 

Engine bed, Pattern for a heavy... I 39 

Engine patterns I 1 

Epicycloidal odontograph I\' 9 

Epicycloidal teeth IV 5 

F 

Finish, Amount of \'I 32 

Flasks in cores. Casting round II 11 

Forms in building skeleton patterns, 

LTse of V 41 

Furnace bell. Mold for a Ill 17 

Furnace hopper, Mold for a Ill 17 

G 

Gear patterns. Construction of IV 15 

Gear patterns. Construction of 

bevel IV 32 

Gear teeth, Involute IV 3 

Gear teeth proportions. Involute. .. IV 11 

Gear teeth to form, Sanding of.... IV 31 



INDEX 



SEC. PAGE 

Gear tooth jigs IV 13 

Gear wheels in cores. Molding large II 30 

Gears, Double helical IV 22 

Gears, Laying out the teeth of 

bevel IV 20 

Gears, Worm IV 24 

Gearing, Spur IV 1 

Gluing stock for cylindrical pat- 
terns VI 16 

H 

Hawser pipe patterns V 14 

I 

Involute gear teeth proportions. .. .IV 11 

Involute odontograph table IV 7 

Involute teeth IV 3 

J 

Joints for covering cores II 18 

L 

Lags, Sawing of \'I 44 

Lathe tools ^'I 7 

Loose pieces ^'I 33 

Loose pieces in double piston valve 

cylinder pattern, Use of I 32 

Low pressure cylinder. Pattern for a I 7 

M 

Model in determining form of pat- 
tern. Use of II 27 

Mold for a double nozzle V 45 

Mold for a furnace bell Ill 20 

Mold for a furnace hopper Ill 21 

Mold for a large steel nozzle or 

saddle V 42 

Mold for a low pressure cylinder.. I 11 

Mold for a piston valve cylinder... I 28 

Mold for a throttle valve V 4 

"Mold for Chilian mill mortar V 55 

Mold for cylindrical and conical 

drum Ill 29 

Mold for double piston valve cylin- 
der I 36 

Mold for hawser pipe V 18 

Mold for nozzle pattern V 22 

Molding a rope sheave in cores. . . II 28 

Molding in cores II 23 

Molding steel truck bolsters V 23 

N 

Nail cores. Use of II 34 

Name plate cores II 20 

Nozzle pattern, A V 20 



Odontograph, Epicycloidal IV 9 

Odontograph table for involute 

teeth IV 7 

Old patterns. Altering of VI 34 



SEC. PAGE 

p 

Pattern, Use of a model for de- 
termining form of II 2'^ 

Pinion housing patterns \' 8 

Pipe patterns, Hawser V 14 

Piston valve cylinder pattern, A I 16 

Plaster paris. Making core boxes 

and patterns with II 3 

Plug core prints. Use of N 20 

Polygons, Table of VI 27 

Propeller wheel in cores. Molding 

of a II 25 

Pulley ring for producing cylindrical 

castings, Use of V 31 

R 

Reverse molding in plaster paris to 

produce core boxes II 3 

Right angle triangle VI 26 

Rope sheave in cores. Molding of a II 28 

s 

Sawing lags VI 44 

Score in a drum pattern. Cutting 

of a VI 1 

Screws in end grain VI 16 

Seat in sweeping a core. Use of a. .Ill 9 
Sectional patterns as applied to 

Chilian Mill mortar V 51 

Sheaves in cores. Molding rope II 28 

Shrink rule. Making a \'I H 

Shrinkage VI 10 

Shrinkage of castings VI 31 

Skeleton pattern for a double nozzle V 44 

Skeleton patterns V 39 

Slag ladle molds, Sweeping of Ill 12 

Slide valve cylinder, Pattern for a. I 1 

Spindle collar, A detachable Ill 13 

Spindle collar, An ecceiitric HI 38 

Spindle for variable pitch score... .Ill 25 

ijpur gearing I\ 1 

Square, A box ^ I 1- 

Stacking of cores II 4 

Steel castings in cores. Making 

small II 1 

Steel castings in cores. Making 

large H 7 

Steel castings in cores. Making 

small II "' 

Steel cutter head in cores. Molding 

of II 26 

Steel flasks in cores. Casting of... II H 

Steel nozzle. Patterns for a V 20 

Steel truck bolsters, Molding of a. V 23 

Striking an ellipse VI 41 

Suction chamber, Sweeping the 

mold for a HI ' 

Sweep work HI ^ 

Sweeps, as applied to a low pressure 

cylinder I ^ 



INDEX 



SEC. PAGE 

Sweeping a cylindrical and conical 

drum Ill 24 

Sweeping a plain cylinder Ill 1 

Sweepnig a steel slag ladle mold.. Ill 12 

Sweeping frame, A double Ill 36 

Sweeping of core for cylinder.... I 37 
Sweeping of mold for a suction 

chamber Ill 7 

Sweeping the mold for a furnace 

hopper and bell Ill 17 

Sweeping rig for variable pitch 

score Ill 26 

T 

T slot cores II 20 

Teeth, epicycloidal I\' 5 

Teeth to bevel gears. Fitting of....I\' 19 

Teeth for worm gears I\' 26 

Teeth for bevel gears, Laying out of. IV 20 



SEC. PAGt 

Teeth, Sanding of gear I\' 31 

Templet work. Cross \' 14 

Thickness strips. Use of Ill 21 

Three-way cock in cores. Molding 

of a II 14 

Throttle valve body pattern, .\.... \' 1 

Tool clearance \"I 32 

Tooth jigs for gears I\' 13 

Triangle, Right angle \"I 26 

Truck bolsters, Molding of steel... \' 23 

Turning wooden balls \'I 9 

V 

N'alve, Pattern for a throttle \" 1 

w 

Warping of castings VI 1& 

Wooden ball turning VI 9 

Worm gears IV 24- 



MAY 6 1907 



